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JOHNS HOPKINS UNIVERSITY,

BALTIMORE.

STUDIES

FROM THE

BIOLOGICAL LABORATORY,

EDITOR:

NEWELL MARTIN, M. A., D. So., M. D.

ASSOCIATE EDITOR:

W. K. BROOKS, Ph. D.

VOLUME II.

Published by N. MURRAY,

Johns Hopkins University.

July, 1888.

PreM of IflMtc medtnwsld, Baltimore* Md.

STUDIES FROM THE BIOLOGICAL LABORATORY

OF THE

JOHNS HOPKINS UNIVEKSITY.

VOLUME II.

CONTENTS.

PAGE

I. A Contribution to the Study of Inflammation as illustrated by induced Keratitis. By William Councilman, M. D. With Plate IV. (Reprint from Journ. Physiol.) 1

II. Some further Observations on Heat-dyspnoea. By Christian

Sihler, M. D., Ph. D. (Reprint from Journ. Physiol.) . 13

m. The Influence of Quinine upon the Reflex-excitability of the

Spinal Cord. By Wm. T. Sedgwick, Ph. B. ... 2:5

IV. The Early Development of the Wolffian Body in Amblystoma punctatum. By Samuel P. Clarke, Ph. D. With Plates I,

n and III 39

V. Notes on the Formation of Dentine and Osseous Tissue. By

Christian Sihler, M. D., Ph. D. With Plate V. . . . 45 VI. The First Zoea of Porcellana. By W. K. Brooks, Ph. D. With

Plates VI and Vn 58

VII. The Study of Human Anatomy historically and legally consid- ered. By Edward Mussey Hartwell, M. A., M. D. G5 VIII. Alternation of Periods of Rest with Periods of Activity in the Segmenting Eggs of Vertebrates. By W. K. Brooks, Ph. D.

With Plate Vm .... 117

A New Method of Studying the Mammalian Heart. By H. Newell Martin, M. A., D. Sc.. M. D. With Plato IX. . Ill)

X. A Note on the Processes concerned in the Secretion of the Pep- sin-forming Glands of the Frog. By Henry Sewull, Ph. D. 131 XI. List of Medusae found at Beaufort, N. C. , during the summers

of 1880 and 1881. By W. K. Brooks, Ph. D. 135

XII. On the Origin of the so-called " Tt«t-Cells" in the Ascidian

Ovum. By J. Playfair McMurrich, B. A. With Plate X. . 147

A CONTRIBUTION TO THE STUDY OF INFLAMMATION AS ILLUSTRATED BY INDUCED KERATITIS. By WILLIAM COUNCILMAN, M.D. (Plate IV.)

(From the Biological Laboratory of the Johns Hopkins University.)

It would be useless to attempt to give here any but the briefest sketch of the views which have been held concerning the origin of pus and the nature of the cellular changes occurring in inflammation since the time of the establishment of the cell theory. A mere recapitulation of the articles written on this subject in the decade of '60 — '70 would fill pages. I will, however, briefly glance at some of the more important ideas which hare been or are held with reference to it.

Rokitansky was one of the first to appear in this field of litera- ture. He, in accordance with the cell theory of Schwann (that is, the free cell formation doctrine), assumed that the pus corpuscles were formed in the exudation which played the part of the blastema. These ideas prevailed generally until 1855, when Virchow was led, from his knowledge of the conuective tissue corpuscle, to dispute the free cell formation, and to apply the law " Omnis cellula e eelluld " to patholo- gical new formations. Virchow held that the pus cell was the direct derivative of the connective tissue corpuscle, because, wherever he found pus he also found connective tissue in some of its forms ; and since he was obliged from his views to have some cell as the parent of the pus cell, he took the connective tissue corpuscle.

Strieker appears as the latest, and certainly the ablest, defender of these views, though they have undergone essential modifications at his hands. He says that the cells of a tissue, when inflamed, return to their former undifferentiated embryonic condition, become amoeboid, and possess the power of dividing indefinitely. This property holds good for all tissues equally ; no matter whether muscle, gland, or ganglion cell, they all can undergo this change and become converted into pus. He holds also that, when the cells return to the embryonic condition, they again become capable of differentiation, and that blood vessels, and even

•1

2 W. COUNCILMAN.

blood corpuscles, are formed in an inflamed part in the same manner as in the embryo. Against these views we have what is known as the " wandering cell " theory, which assumes that the pus cells are white blood corpuscles which have escaped from the vessels. Waller had, as early as 18481, observed the passage of the white corpuscles through the walls of the vessels. At that time his observations attracted but little attention, and were generally distrusted. Cohnheim in 18682 firmly established the fact that the white corpuscles did pass through the vas- cular walls, and, as the result of his study of the inflammatory processes in the frog's cornea, tongue, and mesentery, asserted that the pus cells are white blood corpuscles.

From his study of keratitis, principally induced by cauterizing the centre of the frog's cornea with silver nitrate, he found that, however great the number of pus cells in the inflamed tissue might be, the fixed corneal corpuscles with their processes were unchanged ; that the nuclei of the corneal corpuscles did not increase ; that the clouding of the cornea always began at the periphery and from there advanced to the centre ; that after the injection of pigment granules into the blood some of the pus cells in the cornea were found with similar granules in their bodies. From these four circumstances, supported by the direct know- ledge that the white corpuscles in inflammation did escape through the vessels in large numbers, he concluded that the pus corpuscles were not derived from the fixed cells of the cornea, but had wandered in from without. Strieker, as the result of observations made on the frog's cornea and on the cornea of the cat, asserts that the three first argu- ments are based upon imperfect observations, and that the conclusion formed from the fourth is illegitimate. According to Strieker, the fixed corpuscles do undergo change, their nuclei increase, and the clouding always begins where the injury was inflicted. With regard to the presence of pigment-bearing pus cells in the inflamed cornea after the previous injection of pigment into the blood, he thinks the granules could have passed through the walls of the vessels as easily as the blood corpuscles and have been carried by the lymph streams into the cornea. There they could easily have been taken up by pus cells which were already produced by multiplication from the corneal corpuscles.

Here I may remark that the passage of solid dead particles through the walls of a blood vessel without being carried through by the white blood

4 Phil. Jfay., Vol.xxix.

1 Virohow'i Arch., Bd. xl.

INFLAMMATORY CHANGES IN CORNEA. 3

corpuscles, easily as Strieker thinks it could happen, has up to this time been seen and described by no one. That Cohnheim's descrip- tion does not hold good for all cases of induced keratitis, even on the frog's cornea, is certain ; but the differences can be easily reconciled. Strieker bases nearly all his views of inflammation and of inflammatory new formations on his study of keratitis. I shall, I think, be able to show in this paper that these views, certainly as far as keratitis is concerned, are erroneous, and may possibly be due, even in his case, to imperfect observations.

I can only excuse my temerity in entering upon a field of research in which so many and distinguished investigators have laboured, by the fact that when endeavouring to satisfy myself of the correctness of Strieker's views on the subject, I obtained, after nearly a year's steady work, results which lead to conclusions utterly at variance with his, but which I think go far towards clearing up some of those points in the pathology of keratitis over which there has been most contention.

The corneas of the frog and of the cat have been principally used in my investigations ; the latter animal being chosen for studying the pro- cesses in the mammal from the advantages its cornea offers over many others for investigation, especially in the readiness with which it can be split into layers.

The structure of the normal cornea has been thoroughly investigated by various observers in recent years. We know that its proper tissue is lamellated, and consists of flattened branched cells embedded in inter- communicating centres (the serous canaliculi) hollowed out in an inter- cellular fibrillated ground substance, which makes up the larger portion of the corneal mass ; that the tissue is well supplied with nerves arranged in plexuses which become finer towards the conjunctival surface ; that with hematoxylin or gold the cells stain and are seen to communicate by fheir branches ; and that with silver nitrate the ground substance is tinted, while the cells and cell spaces are left unstained. Hema- toxylin also stains the nerves, while with silver preparations the lymph channels in which the larger ones run are seen as colourless lines.

We also find, even in the normal cornea, another set of cells, which cannot be considered a part of its fixed histological elements. Their numbers are variable ; in some corneas very abundant, in others few : in animals of the same species sometimes they are found in greater numbers at one portion of the tissue, sometimes at another. In -fresh preparations they can be seen to pass by active amoeboid movements from one place to another, and they never, so far as we can see, stand in any fixed his-

•1—2

4 H". COUNCILMAN.

tological relation to the other elements of the tissue; these are the " wan- dering cells." Their position is not at all constant ; sometimes we find them lying in the cell space along with the branched corpuscles, sometimes in the narrow communication between two spaces, sometimes as long drawn out rods in the tissue between the fibres (b, Fig. 1, PL IV.), some- times in the nerve lymph channels, and in- one preparation I have been so fortunate as to get one seemingly in the act of passing from the nerve channer into a cell space communicating with this, half of its body lying in the channel and half in the space. They can be clearly dis- tinguished from the branched corpuscles both in the fresh condition and when stained ; they are much smaller, and with the usual reagents they stain more brilliantly than the others. In fresh preparations in aqueous humour they are easily recognized by their amoeboid movements, their greater index of refraction, and their granular contents.

So much for the normal cornea. We will now take up the patho- logical changes which occur after an acute keratitis has been induced, commencing with those seen in the frog's cornea.

I have employed various means for exciting inflammation here The passing of a thread through the centre of the cornea and bringing it out through the sclerotic, the application of various caustics, such as croton oil, silver nitrate, caustic potassa, and the hot iron (actual cautery). With few exceptions they produce results relative to the severity of the sti- mulus used. Agents such as the hot iron, which at once kill the tissues with which they come in contact, will, of course, produce less inflammation in surrounding parts than those like the thread, whose action is more or less gradual. A method which I have used on the frog's cornea with excellent results has been to pass a thread through the membrana nictitans and then make several pricks in the cornea with a needle. The inflammation produced by this method will be discussed Separately, since results are in this way obtained which at first seem perplexing.

As one of the most typical, I will take a cornea which has been inflamed by touching it at the centre with a crystal of silver nitrate.

This may be examined after various intervals of time have elapsed, both in the fresh condition and after staining. About twenty hours from the application of the caustic the most important changes can be seen. To examine fresh, it is necessary to puncture the sound eye and collect the aqueous humour on a slide ; the inflamed cornea is then care- fully excised and spread out in this, with the posterior surface uppermost

INFLAMMATORY CHANGES IN CORNEA. 5

To avoid folds in the tissue it is better to make three or four incisions at the edge, extending for some distance towards the centre, before putting on the cover slip. The powers I have found most satisfactory to use have been the No. 2 immersion of Zeiss (yf) and the E of his dry system (£).

The first thing noticed here is that the large branched cells are visible ; in the normal they cannot be made out at all directly after the cornea is cut out, and only appear after an interval of half an hour to an hour. They are no more granular than in the uninfiamed, and pre- sent no changes from the normal an hour after the excision of the latter. Why they become at once visible I do not know ; it may be due to some change in the refraction of the ground substance caused by the greater amount of fluid now in the tissue, or to some change having taken place in the corpuscles and only revealing itself in this way, or to both.

The wandering cells are present in vast quantities, exhibiting the most active -and varied movements ; while in the normal cornea, as before remarked, we only occasionally see them. Spmetimes one may be seen to send out a long process, at the end of which a knob presently appears, which, growing larger and larger, finally becomes the main body of the cell : as though in this way it had passed from one space to another through a narrow communication. Sometimes we see them as more or less irregular bodies, undergoing changes of form and not of position ; again as the long, staff-like bodies spoken of in the normal cornea. They are present in the greatest numbers at the edge, becoming fewer as we proceed to the centre. Since in the fresh specimens our observations must be made on the whole thickness of the cornea, all these changes become much more clear and can much better be studied after it is stained and split up.

For staining I always use the double staining in silver with haema- toxylin or carmine, the former being much preferable for the frog. The cornea is exposed by pushing the eye upward from the roof of the mouth, and rubbed smartly with the solid crystal of silver. At the expiration of ten minutes it is cut out, and exposed in glycerine to the action of diffused daylight ; when it becomes of a light brown colour it is split up and stained in one of the two reagents mentioned. With care the cornea of the frog can easily be split into eight or nine layers. I vastly prefer this method of staining to the gold chloride method, which has hitherto been almost exclusively used in these investigations. It has the great advantage of being always certain in its results ; while

6 W. COUNCILMAN.

gold, although sometimes giving us beautiful preparations, is the most uncertain of reagents, and its success depends for the most part on unknown circumstances. Another great advantage is that we have both the negative and the positive picture at once ; the cell space shown with the cell within, and the relation of the one to the other always is kept in view. The preparations are mounted in slightly acidulated glycerine.

In preparations of the twenty-hour cornea examined after this treatment we can easily make out three distinct parts : — A central one, on which the caustic was applied, and which is now represented by a black scar, in which the cell spaces are imperfectly seen. Around this is a zone of variable width, in which absolutely no change from the normal can be made out ; here we see the sharply-defined cell space, with the nucleus, or, in deeper staining, the body of the cell within. The width of this zone is dependent on the extent of the injury, the length of time which has elapsed since its infliction, and on the general irritability of the tissues of the animal used. Without doubt, from the same amount of irritation, the extent of the pathological changes in some animals of the same species is different from that seen in others.

This zone passes, separated by no well defined line, into the outer- most one. In this, along with the corneal corpuscles, other elements can be seen in numbers far in excess of the branched cells and always in the greatest quantity at the outer edge. These other elements stain in all respects similarly to, and are always of the same size as, the wandering cells previously described in the normal cornea. They can always be distin- guished from the branched cell, even when lying in the same cell space with it. In one place we see the nerve channel filled with them, in another we see them lying in the tissue between the fibres, and elongated until they have the appearance of rods. Again we see them in the cell spaces or in the narrow interspace between two cells ; their form always influenced by the dimensions of the cavity in which they lie. Often where they are most numerous in the tissue the branched corpuscles cannot be made out at all. It may be that these are simply concealed by the vast numbers of the others, or it is possible that the fixed cor- puscles have then been absorbed or destroyed by the young and vigorous strangers.

In no case do we see in the corneal corpuscles proper, any indications which would lead us to suppose that multiplication had occurred or was taking place. They stain with reagents as did the normal, and the nucleus always has the same shape as this, except in instances where it

INFLAMMATORY CHANGES IN CORNEA. 7

may be indented by pressure from a wandering cell lying in tbe same space, as represented at a, in Fig. 1, taken from the normal cornea. If the cornea be examined at an earlier period, say twelve hours after the injury, these wandering cells will be confined to a small area at the outer edge ; if later than twenty hours, forty, for example, they will be found to fill almost the entire cornea, completely obliterating the unchanged zone in some cases.

If we examine the surrounding portions of the sclerotic and conjunc- tiva we find the blood vessels full of cells just like these, and the whole tissue there also infiltrated with them.

A still further proof that these wandering cells enter the cornea from without is furnished by the result of the injection of finely divided colouring matter into the blood, according to the method of Cohnheim, whose results in this respect I can completely confirm.

If the cornea is cauterized shortly after the injection of cinnabar into a lymph sac or the anterior abdominal vein and examined after the usual time, we find among the wandering cells a great many in which pigment granules are plainly visible, though they differ in no other respect from the others. Sometimes a few granules can be seen in the tissue not inclosed in the cells. These may be accounted for by supposing that they were here dropped by the wandering cell which brought them from the vessel. Strieker himself says that he and N orris have seen one wandering cell transfer to another cell of the same nature some of the vermillion granules contained in its substance. Since the vermillion granule can in nowise contribute to the nutrition of the cell, and forms rather a heavy load to be carried round, we can see excellent reasons why the cell^vould be willing to throw it away. The number of cells containing these granules is far too large to suppose they could have gotten them in any other way than by taking them up in the blood vessels.

The inflammation produced by methods involving a laceration of the corneal tissue gives some results differing from those last described. Here, as in the^last case, we see the peripheral portion of the tissue infiltrated with wandering cells ; but we see them also elsewhere. Around the spot where the injury was inflicted we see cells of the same appearance and offering the same variety of form and position as those at the outside, and here narrowing the zone, which in the cauterized corneas we have described as free from them, very materially. How came these cells here ? From the outer edge they could not come, for we have lying between this and the centre a zone which, in the earlier stages of the

8 W. COUNCILMAN.

process certainly, is free from them. If now we combine both methods of producing the inflammation, and having cauterized two corneas in the centre, we make a prick at the outer edge of the cauterized spot of one, and examine the two after the usual interval of time, we shall find plenty of wandering cells around the laceration in the cornea whose tissue. was punctured, and none at the same spot in the other. Only one conclusion is possible, that they have entered the cornea where its substance was broken. This is easily comprehensible, since a keratitis can scarcely be produced in this way without involving at the same time an extended conjunctivitis, and as a consequence of this having quantities of white blood corpuscles in the conjunctival secretion. From this source they could easily enter the tissue where broken.

The results obtained after passing the ligature through the membrana nictitans point clearly to this. Here a violent conjunctivitis is necessarily set up ; many blood vessels in the membrane are ruptured and plenty of white corpuscles poured out. As a consequence, in these preparations we have a very large number of wandering cells at the point where the prick was made; in some cases they are so plentiful that everything else is obscured. After the injection of pigment granules these wandering cells also contain them. No change is seen in the branched corpuscle at either place.

Proceeding now to the cat's cornea, we meet here, even in the normal state, some difference from that of the frog. The corpuscles (Fig. 2), are smaller, are more numerous, and the cell spaces communicate by larger passages than in the frog. The brightly-staining wandering cells in the normal cornea are fewer in number than in the frog's confea, and mostly found in the cell spaces. Their special characteristics will be described when we come to speak of the pathological changes.

As a means of exciting inflammation I have, following Strieker, used the solid stick of caustic potassa, and found it vastly superior to any other agent. A young cat is preferable to an old one, from the fact that the cornea of the former is much more easily split into its lamellae than that of the latter. The animal is first etherized and the cornea touched with the caustic ; particular care must be exercised in doing this, as the potassa melts so rapidly on contact with the moist surface that there is great danger of its involving too great an extent of tissue. To avoid this the caustic stick must be pointed (which is easily effected by holding it in a stream of water), and the cornea previously carefully dried with filter paper. By varying the period of contact, an eschar

INFLAMMATORY CHANGES IN CORNEA. 9

extending only a few lamellae in depth or one involving the whole thickness of the tissue can be produced. The animal is then left in quiet and the cornea cut out and examined after periods of from 14 to 60 hours. The silver staining, before removal, and the after staining, with carmine, are used. If we examine such a cornea, say 40 hours after cauterization, and as yet unstained by carmine, the changes found can be divided into two heads. Of these the first will comprise the changes around the outer corneal edge, and the second those in the immediate neighbourhood of the eschar. In the first we find the cell spaces some- what larger and the communications between them wider than in the normal cornea. Scattered about through the tissue we find the strongly refracting rod-like cells, appearing very similar to those we have seen in the frog. If the silver staining has been very deep we find the silver precipitated in the substance of the corneal corpuscle as well as in the ground substance, leaving a clear unstained nucleus in every space.

In the immediate neighbourhood of the eschar the change is more pronounced, and different from anything we have hitherto seen. These changes are all the more important to us, since it is here that Strieker says the corneal corpuscles are undergoing the most rapid proliferation. In the silver preparations we see, lying in the coloured ground, groups of small white spaces with dark brown lines separating them from one another (Fig. 4) ; these groups correspond in shape to enlarged cell spaces. Strieker seems to have confined his observations to this spot, and explains the picture by supposing the corneal corpuscle has here broken up into a number of smaller cells, and that the brown lines mark off the new cell limits.

Let us now see what the carmine staining shows in the two parts. In the outer ring we have (Fig. 3) in each of the slightly enlarged cell spaces the large oval nucleus of the branch cell totally unchanged, and staining in all respects like the normal. In rare cases we find (as is also the case with the normal) two of these nuclei in a space. In addition to these there are other cells, which, from their characteristic appearance, merit a mqre detailed description. These have a differ- ence in shape according to whether they are found in the cell spaces and nerve channels, or in the proper corneal substance, there lying between the fibres. In the former they are round, with a brightly- stained granular nucleus of the shape of a horseshoe, and correspond to the wandering cells in the normal cornea. Under high powers (800 — l'OOOx) the apparently single nucleus is usually found to be

10 W. COUNCILMAN.

composed of three or four small bodies lying in juxtaposition, the mass being always arranged in the shape of a horseshoe.

When lying in the tissue between the fibres they are elongated, and then appear as jointed rpds, each joint having the highly-stained granular nucleus. At first sight these rod-like bodies would seem to be entirely different from the round cells in the spaces ; but, on closer inspection, at different places every variation can here be seen, from the slightly elongated cell with a horseshoe nucleus to the long rod-like cell. If we now stain some of the blood of the cat, we find that the white blood cells have a nucleus of this horseshoe shape and stain in all respects like these wandering cells.

Proceeding now from the corneal edge towards the eschar, we come to a region where the corneal corpuscles are wanting, passing on the way through a district where they have taken on changes which will occupy our attention presently. Beyond this line, which can be seen by even a simple lens, the corneal corpuscles are dead — have been destroyed by the caustic. The cell spaces can be seen, most of them much shrunken, but no nucleus in them, or anything which would afford us proof of the presence of a corneal corpuscle. Lying in these cell spaces, but still more in the tissue between them, are seen multitudes of cells before described, at the scleral edge. These cells become more numerous as we proceed, until we reach a territory where the cell spaces are filled with them (Fig. 5). The spaces here are enlarged, and the communications between neighbouring ones are wider ; spaces and communications are all full, and no one comparing these cells with those at the outer (i.e., the scleral) edge can doubt for a moment that they are similar.

Beyond this line of general infiltration the tissue is totally destroyed. By this I mean that not only its living protoplasm is killed, but its physical properties are also altered. Nothing of the cell spaces can be seen, and apparently the wandering cells can make their way no further. At the point of general infiltration the tissue sloughs.

In corneas examined 10 to 14 hours after cauterization this district of general infiltration is wanting ; no wandering cells are seen there. In the other district, however, that around the outer corneal edge, the wan- dering cells are numerous ; sometimes so many will be seen that the feintly-stained nucleus of the branched cell is entirely obscured, the wan- dering cells filling up the space. From this edge they become fewer and fewer as we proceed towards the centre. The line of corneal corpuscles marking off the portion of the cornea in which the corneal corpuscles were destroyed by the caustic from that portion of the cornea where the

INF LAMM A TOR Y CHA NOES IN CORNEA . 1 1

corpuscles were uninjured, is not now so well seen, as these corpuscles have as yet taken on no change by which we can distinguish them. We readily see, however, even here, where the living tissue ends. Now it is beyond this line that we get from the silver preparations of a later period of inflammation the appearance as though the corneal corpuscles had proliferated. Here were the colourless areas subdivided by brown lines. From this place Strieker's drawing was made, and here he, judging merely from silver staining of corneas, taken always at a fixed time after the cauterization, supposed the proliferation to have been most rapid. Further examination by better methods, and at different periods, after cauterization, shows us that there is here nothing to proliferate. The tissue is as bare of living corneal corpuscles as a sheet of paper. In 48-hour preparations the line of demarcation is more evident and the tissue beyond more infiltrated with cells than in the 40-hour preparations. In all the portion first described, that along the edge of the sclera, no change can be seen in the nuclei of the branched cells. In corneas examined 60 to 80 hours after cauterization, that portion of the tissue surrounded by the infiltration is converted into a slough, which easily comes away, and the peripheral portions, the district around the sclera, still contain wandering cells.

In the corneal corpuscles which form the line outside the zone of infiltration, and which indicate the separation of the dead from the living proper corneal tissue, we find changes as early as twenty hours after cauterisation. These changes are at this period only shown by a brighter staining ; the whole substance of the cell here stains and else- where only the nucleus. At a later period (30 to 40 hours) the nuclei can be seen in different stages of division, and at the same time long processes are sent out from the cells into the dead tissue. These processes become longer (Fig. 6), nuclei pass from the old cell up into them, and thus they form in the dead tissue new corneal corpuscles, but never pus. These processes and new cells stain in all respects like parent cell from which they originated, and the nuclei have the same shape as in the old cells, though they stain more brightly, and are more granular.

The appearance of a segment of the cornea taken three or four days after injury, in which the branched corneal corpuscles are undergoing this proliferation, is most beautiful. The nuclei of the new corpuscles divide rapidly, and in some as many as four can be seen. Even if the whole cornea is destroyed with the exception of a small strip along the outer edge, the corpuscles limiting this take on this renewed activity'.

12 W. COUNCILMAN. .

The difference between these two processes — the suppurative, on the one hand, in which the wandering (ells are the agents, and the regenerative, on the other, by which new corneal corpuscles are produced from corneal corpuscles — is so clear that no one seeing them side by side could mistake them. In no tissue in the body can the processes of repair be so clearly studied as in the cornea ; and in no other tissue can the wandering cell theory as to the origin of pus corpuscles be so clearly proven to be correct.

DESCRIPTION OF THE FIGURES. PL. IV.

Fig. 1. — Normal cornea of frog, stained with hematoxylin. Two of the branched corneal corpuscles are shown with a wandering cell, a, lying in the cell space with one of them, b b represent two of the wandering cells in the subitanoe of the cornea ; these have taken the elongated form.

Fig. 2. — Normal cornea of a oat, stained with silver and carmine. The ground sub- stance is stained brown with the silver, leaving the oell spaces unstained. In these are seen the nuclei of the branched cells stained with carmine, b b, two wandering cells in the cell spaces.

Fig. 3. — Scleral edge of cat's cornea fourteen hours after central inflammation. The wandering cells, b b, are increased in number, and the communications between the spaces are larger than in No. 2. Silver and carmine.

Fig. 4. — Area of general infiltration forty hours after central inflammation. The oell spaces are greatly enlarged, and broken up into small areas by the brown silver lines. The ground substance is reduced in amount, in some places represented only as small islands.

Fig. 5. — Innermost limit of area of general infiltration. Here, as in No. 4, the cell spaces are greatly enlarged, and divided into small areas, in each of which the brightly- stained horseshoe nucleus is seen. From this point to the centre no cellular elements are found. Silver and carmine.

Fig. 6. — Two corneal corpuscles, which have taken on regenerative changes. The nuclei have increased in number, and long processes which are much branched have grown out from the parent cell.

directly on the centres in the medulla, though, if bo, producing leas effect than the peripheral stimuli.

In the following short communication, I propose to give further support to the first statement, and discuss the second as well as another which I touched in the published essay, namely, the action on the medulla of higher temperatures than those used in my former investi- gations.

I feel the more inclined to add further proofs to support the con- clusions which I reached, as views contradictory to them and based on Goldstein's experiments, which I have shown to be imperfect and ^conclusive, are taught in several text books of Physiology, and apa gaining ground in the medical profession.

Foster says, on page 377, 3rd Edition: "If the blood in the carotid artery in an animal be warmed above the normal, dyspnoea 18 at once produced. The over- warm blood hurries on the activity

12 W. COUNCILMAN. .

The difference between these two processes — the suppurative, on the one hand, in which the wandering (ells are the agents, and the regenerative, on the other, by which new corneal corpuscles are produced from corneal corpuscles — is so clear that no one seeing them side by side could mistake them. In no tissue in the body can the processes of repair be so clearly studied as in the cornea ; and in no other tissue can the wandering cell theory as to the origin of pus corpuscles be so clearly proven to be correct.

DESCRIPTION OF THE FIGURES. PL. IV.

Fig. 1. — Normal cornea of frog, stained with haematoxylin. Two of the branched corneal corpuscles are shown with a wandering cell, a, lying in the cell space with one of them, b b represent two of the wandering cells in the substance of the cornea ; these have taken the elongated form.

Fig. 2. — Normal cornea of a oat, stained with silver and carmine. The ground sab- stance is stained brown with the silver, leaving the cell spaces unstained. In these are seen the nuclei of the branched cells stained with carmine, b 6, two wandering cells in the cell spaces.

"Fig. 3. — Scleral edge of cat's cornea fourteen hours after central inflammation. The wandering cells, b b, are increased in number, and the communications between the spaces are larger than in No. 2. Silver and carmine.

Fig. 4. — Area of general infiltration forty hours after central inflammation. The cell spaces are greatly enlarged, and broken up into small areas by the brown silver lines. The ground substanoe is reduced in amount, in some places represented only as small islands.

Fig. 5. — Innermost limit of area of general infiltration. Here, as in No. 4, the cell spaces are greatly enlarged, and divided into small areas, in each of which the brightly- stained horseshoe nucleus is seen. From this point to the centre no cellular elements are found. Silver and carmine.

Fig. 6. — Two corneal corpuscles, which have taken on regenerative changes. The nuclei have increased in number, and long processes which are much branched have grown out from the parent cell.

directly on the centres in the medulla, though, if so, producing less effect than the peripheral stimuli.

In the following short communication, I propose to give further rapport to the first statement, and discuss the second as well as another *hich I touched in the published essay, namely, the action on the ntedalla of higher temperatures than those used in my former investi- gations.

I feel the more inclined to add further proofs to support the con- clusions which I reached, as views contradictory to them and based on Goldstein's experiments, which I have shown to be imperfect and inconclusive, are taught in several text books of Physiology, and we gaining ground in the medical profession.

Foster says, on page 377, 3rd Edition : " If the blood in the carotid artery in an animal be warmed above the normal, dyspnoea *• at once produced. The over- warm blood hurries on the activity

14 C. SIHLER.

of the nerve cells of the respiratory centre, so that the normal supply is insufficient for their needs. The condition of the blood then affects respiration by acting directly on the respiratory centre itself."

Fick says, on page 266 of his Physiology, 2nd Edition : " If au animal is artificially heated several degrees above its normal tempera- ture, the respirations become deeper and very much more frequent, even if the quality of the blood is in nowise changed ; yes, even when by ener- getic artificial inflations arterialisation of the blood is insured ; indeed, it is quite impossible in an animal thus super-heated to produce the state of apnoea. That reflex influences do not come into play here — e.g., from the heated skin — can easily be proven by the following experiment. By application of the proper apparatus one can succeed in heating nothing but the blood flowing in the carotid arteries. As soon as that takes place the frequency of the respirations rises just in the same way as if the whole animal had been heated. From that one must conclude, that it is the increase of the temperature in the respiratory centre itself which increases the irritability, and at the same time diminishes the resistance, so that the exciting agent produces in the same unit of time deeper and more frequent respirations."

In an article on Progressive Pernicious Anaemia, by Herbert Jones, published in the Practitioner, February, 1880, we read this : 1 Heat is also a stimulant to the respiratory centre in the medulla oblongata, by which the movements of respiration are regulated, and as#Fick and Goldstein have shown, when warm blood is supplied to this centre the respiratory movements become quicker and deeper until marked dyspnoea takes place, although the blood which is circu- lating in the rest of the body still retains its normal temperature."

I let Exp. 1, see Table I., precede the remarks which I wish next to make. The observation it records, like the rest of my experiments, was carried out on a dog. The temperatures, during my observation, were taken in the rectum or vagina.

I had various reasons for undertaking this experiment. In the former investigation I had found that one animal might breathe 200 to 300 times a minute without its temperature going up, and vice versd, the temperature of another animal might go up several degrees while the respirations went up from 26 to 62 per minute only, the cord in the latter being divided in the lower cervical region.

HEAT-DYSPNCEA.

15

Table I.

0 O

1

I

o

1

2

8

4 5 6 7 8 9 10 11

lime.

10.05 40

48 53 58 11.05 10 17 20 29 35

12

40

13

45

14

55

15

12.80

16

42

17

44

18

1.00

19

1.01

20

06

21

11

22

15

23

20

24

25

25

80

26

31

27

34

28

3.15

29

4.27

30

5.10

31

25

32

80

88

47

84

57

85

6.21

•a

|

24 41

44 42 44 44 46 48 48 49

50

85 87 38 87 38

50 58 49

60 60

§

I

38*9

88-9

88'9

88*9

39

89

39

891

39-1

39-1

39-1 88-9 389

39

39

39

39

891

89-2

898

89-8

376 87-8 38

38*5 38*9 89*6

is Si

P4 M

J

28

86 120 132 200 204 268 280 280

216 87 30

36

152 240

228 810

280

18 18 20

18 22 24

Wednesday.

Tracheotomized.

Head only in apparatus, breathing warm air through tube.

Panting.

Artificial respiration for 2 minutes with cool air, apnoea for J minute ; shallow respira- tion for 1 minute ; out of apparatus.

Artif. resp. for 2 min. ; no apnoea.

Artificial respiration ; apnoea of 1 J minute. Placed in apparatus ; head free.

Artif. respiration for 2 minutes ; no apnoea.

Panting.

Artif. respiration for 2 minutes ; no apnoea.

Taken out of apparatus.

Cord cut.

Placed in apparatus ; head and arms free.

Artif. respiration ; apnoea of over 1 minute.

16

C. SIHLER.

86 87

88 89

40 41 42 48 44 45 46 47 48

Time.

6.28 86 46 58

9.20 25 10.80 85 88 48 47 50 55

1-

60 60 60

60 68

55

50 49 49

I

89-5 39-7 40 40-1

87 87 40*8

41-4

42

t

& 2

Ji

24 21

19 26

40

100

425 156 42-5

Wednesday. ! Artificial respiration ; apnoea of } minnte.

Artif. reap, for 2 min. ; apnoea over 1 min.

Thursday.

Artif. resp. of 2 min. ; apnoea of 1 J min.

Placed in apparatus.

*

Artificial respiration ; apnoea of £ minnte.

Artificial respiration ; apnoea of £ minnte. Begins to pant.

Artificial respiration ; no apnoea.

These facts being brought oat on different animals, one object here was to try one and the same animal. That is, to take account of increased temperature, if there was any, and increased number of respirations before the cord was cut and after the cord was cut in the same dog.. It will be seen that the present results agree with the former conclusions. The same dog is made to breathe 240 times a minute (Obs. 21) while haying a temperature of 39 (38*9 had been the temperature of the dog when the experiment began). When we look, however, for the respiratory rate at the temperature of 39, after the dog's cord had been divided, we find it (Obs. 34) 22. And if the objection were to be made that the dog was unable to breathe rapidly on account of the section of the cord, by looking towards the

HEAT-DYM>AT(EA. 17

*

end of the table it will be found that this is not the reason, for the dog can make as many as 156 respirations in a minute.

We see, then, that in the same dog, when exposed to warm air acting on a large surface, connected by afferent nerve paths with the medulla, the respirations may go up enormously without the animal's temperature rising ; and, on the other hand, the respirations may go up less than 25 per cent., while the temperature increases over one degree Celsius ; in this latter case the greater part of the skin being thrown out of nervous connection with the medulla by previous section of the cord.

It will further be observed, by glancing over the table, that artificial respiration was carried on several times. Some of these produced apnoea, others did not. At 12.44 (Obs. 17), while the animal was at 38*9°, and not in the warming apparatus, apnoea of 1£ min. was pro- duced. At 1.15 (Obs. 22), while the animal was at 39°, i.e., only 0*1° higher than before (practically not higher at all), the same amount of inflation was not successful. That the 0'1° of temperature was not the cause for this condition is shown further on. When the cord had been cut apnoea was successfully produced, although the temperature of the animal had* risen not 0-1°, but 1*1°. Again, when finally (Obs. 47) the tempera- ture had reached 42*5, and the respirations 156, the efforts at producing apnoea were again fruitless. It is clear from this that it is not the temperature of the blood per se which makes apnoea impossible. We see apnoea may be possible both at normal and at elevated temperatures ; it may also be impossible both at normal and at elevated temperatures; the reason of the difference being that the dog cannot be made apnoeic if he pants vigorously. Of course there is a limit when artificial respiration will at times be successful and at times not : just when the respiration begins to grow rapid and take on the character of panting, as is shown in Table II., when the dog had the head only in the apparatus. Here, then, we have another support for our conclusions. In the last paper it was shown that it was not the heat acting on the centres which produces this con- dition of the animal, in which it cannot be made apnoeic. The present observations show the other side of the same fact, and make it evident that peripheral influences, due to exposure of the skin only, may be so strong that they do not allow the centre to come to rest, although there is no venosity of the blood to act as a stimulus, nor has the animal's temperature risen more than a degree.

In the third place, it will be seen (Obs. 46 — 48, Table I.), that the dog did commence to pant — with the cord cut — after he had reached a

temperature of 42.

*2

18

C. SIHLER.

Let me recall now one of the conclusions of my previously-published paper : " The increased respirations .... are due to two causes, skin stimulation and warmed blood." A somewhat closer consideration makes it evident that the experiments there given were not sufficient to show that the warmed blood has any direct central effect : for although by section of the cord in the lower cervical region a large part of the skin was thrown out, yet the fore limbs, neck, and sensitive head, mouth/ and tongue remained in connection with the medulla ; and although in the experiment the direct action of the heated air from without was prevented by keeping the animal's head, &c, out of the warm chest, yet this did not preclude the heating of the nerves of the skin of those parts from within by means of the blood which had been heated in the other parts of the body flowing into them.

To show how sensitive the mucous membrane of the mouth and the tongue is, I add Exp. 2, Table II.

Table II.

December 3rd,

1879.

No. of observation.

Time.

•

1

7.53

42

39

n

2

55

Head and fore-feet placed

in

8

8.01

40

88*9

40

apparatus.

4

06

40

89

52

5

08

40

89-1

90

6

09

40

39'1

152

7

12

40

89-1

66

Nose free.

8

15

39

39

92

Nose back in oven.

9

16

40

39-1

160

10

18

40

89-1

Dog pants.

In this experiment it was the aim to have the surrounding air which the animal took into its mouth not very hot, not warmer than the blood was when the dog began to pant in the experiment above referred to. The experiment shows that exposure of a small part of the body, mouth, neck, and fore limbs, to this not very high temperature is sufficient to

HEAT-DYSPNCEA.

19

produce quickened breathing and even panting, although the animal's temperature is not raised. Human experience agrees with this ; if in the effort of getting into perspiration by means of a hot-air bath one keeps the head under the sheet and thus breathes air of about the body temperature one finds the respirations similarly increase in frequency.

In the former paper it was shown, that the temperatures there employed (41*3) did not produce the panting when the cord had been cut, and it was left for further investigation whether higher blood tem- peratures might produce such an effect by action on the centres directly. The setting in of panting in Exp. 1 when the dog had reached the temperature of over 42 might be adduced to support the view, that the heat in conditions like the above acts centrally, the cord having been cut. But the foregoing remarks show that such a conclusion would not be justified, as the peripheral influences from mouth and head are not excluded ; nor were those from the lung nerves. I cannot see how to throw #ut these peripheral influences altogether, and the question, possibly, must remain an open one, although there cannot be adduced any fact showing a direct action of heat on the centres.

A third experiment, see Table III., however, was devised in which peripheral influences were eliminated as much as possible.

Table III.

January 9, 1880.

o

1

2 3

4

5 6

4

s

9 10

Time.

.3 J

II

«H O

9. fi

&

10.80

36*7

11.40

14

32

12.48

13

80

12.52

40

80

1.35

57

31

2.53

50

34

3.03

50

86

| 3.10

53

37

3.24

60

88

8.29 i

60

38-5 ,

ft

7 6 6

6 9 9

10

10

9

Cord and pneuinogastrics are cut.

Placed in apparatus; head and fore limbs free.

Ice in cloths placed around bead.

2—2

20

C. SIHLER.

*8

. in

•♦-1

03

•

«M O

•8

Time.

Temp appars

Temp anim

Jl

e

10

11

3.45

65

88*9

12

4.14

67

40

8

18

17

67

40*5

10

14

24

63

41

18

15

30

60

41-8

12

Artificial respiration necessary.

16

81

Respiration shallow and weak.

17

83

59

Artificial respiration necessary.

18

84

41-4

12

Artificial respiration necessary.

19

36

59

Respirations shallow.

20

40

41-7

12

Muscles twitching.

21

45

18

22

49

58

42

20

Efforts at respirations rather than respira- tions.

23

50

42

16

•

24

55

42

Artificial respiration.

25

57

58

42

Dog died.

Table III. then shows that when cord and pneumogastrics are cut the increase in the number of respirations is very low indeed. This certainly does not look as if the hot blood had the power to directly diminish resistance and increase the irritability of the respiratory centre. It is not without interest to observe how the panting can be produced if the cord is cut and the pneumogastrics preserved — in that case, however, the temperature must be. raised considerably — and how it can likewise be produced when the pneumogastrics are cut and the cord left intact, in that case the temperature need hardly be raised at all. But when both cord and pneumogastrics are cut panting is not seen, excepting under certain artificial conditions.

The next question, then, would be how much is due to the peripheral stimulation of the vagus-endings in the lungs by the increased tem- perature, and do they act just like the nerves of the skin ? Are they sensitive to warmth ?

Exp. 4, Table IV., may help to answer this question.

HEAT-DYSPNCEA.

21

Table IV.

March 4th, 1880.

of tion.

â– M

of lion.

No. observe

Time.

â– 8 5

1

7.35

39-2

36

The temp, in this exp. from No. 9 onwards refers to the heated air in the can. The evening was very warm and close.

2

45

89'2

45

3

55

34

39-1

70

4

8.00

89-2

184

5

15

Cord cnt.

6

23

88*8

50

7

28

38*8

47

8

40

38'5

38

Dog's trachea-tube connected with a large tin containing water at elevated temp, and Ba. (O.H.),.

9

55

48

38-4

86

10

9.05

50

88-4

82

11

23

53

38-8

29

12

38

53

38-8

28

18

43

Placed in warm apparatus.

14

10.06

59

88-8

82

15

12

61

39*2

52

16

15

58

895

60

17

20

60

39-9

90

•

18

25

40-4

160

19

28

60

40-5

176

Pneumogastrics cnt.

20

32

60

40-9

232

March 5th.

21

8.40

345

21

22

45

41

•

Placed in apparatus.

28

9.08

52

85

16

24

37

63

37

14

25

48

54

38

18

26

10.01

55

89-2

19

27

06

49

40

20

*

28

20

50

41

8

29

30

51

41

14

80

40

50

41-8

10

31

48

50

42

44

Artificial respirations for two minutes.

82

55

50

42-5

52

33

11.00

51

42-6

52

34

05

52

48-2

36

35

15

43*6

156

22 C. SIHLER.

We can gather, then, from Table IV. that giving the animal warm and moist air to breathe did not seem to have any effect on the peripheral vagus fibres, the animal was not made to pant thus; and, again, cutting he nerves did not stop the panting after it had once been set up. The same observation was made on a dog in which the cord was intact, the animal breathing hot air. The respirations were not permanently diminished by cutting the vagi.

But why did the dog not pant the next day after reaching a temperature of 41 ? Or why not in Table III. ?

I may add here that the dog would not have reached before dying the high temperatures which it did in Table IV. if artificial respiration had not assisted him ; and, further, the observation has repeatedly been made, that the respirations go up in frequency during artificial respiration and remains high a little time afterwards.

Regarding the depth of the respirations, I cannot support the state- ment that they grow deeper. Tracings which I have taken show that they grow more shallow, as it also appears to ordinary observation. Accidentally I found out, I think, how Fick's statements, that they grow deeper, came to be made. In an experiment which I made the board on which the dog rested got a little too hot accidentally, and then the respiratory movements grew deeper. As soon as the animal was protected from pain they went back to their normal character, showing more limited excursions than the respiration at the normal temperature.

THE INFLUENCE OF QUININE UPON THE REFLEX- EXCITABILITY OF THE SPINAL CORD. By Wm. T. SEDGWICK, Ph. B., Fellow of the Johns Hopkins University, Baltimore, U.S.A.

It is the object of this paper to describe a series of experiments which seems to indicate a different explanation from that commonly accepted for the influence of quinine upon the reflex-excitability of the spinal cord. A knowledge of the real action of this drug is particularly desirable at the present time, because Setschenow's theory of special reflex- inhibition centres has been so often and so successfully attacked that the arguments drawn from the marked effect of quinine upon reflex-irrita- bility are to-day, perhaps, among the best reasons for retaining it.

The theory of Setschenow1 was originally offered to explain the great loss of reflex-irritability which is the uniform result of stimulating with sodium chloride the optic lobes or optic thalami of the frog's brain. It has also been looked upon with favour as accounting most easily for that singular rise in reflex-irritability which follows division of the medulla in the normal frog.

Herzen2 weakened the argument for the existence of these centres by showing that a depression of irritability was not limited to stimula- tion of the optic lobes and thalami, but might be induced by stimulation of the cord itself. Goltz8, sines that time, has removed the necessity of retaining the theory of Setschenow to explain the increased irrita- bility of the normal frog after division of the medulla by bringing forward his theory of simultaneous stimulation. Besides these investi- gators, Freusberg4 and others have tested and finally abandoned the doctrine of special reflex-inhibition centres. Nevertheless, this doctrine still offers the readiest explanation of numerous phenomena in physio-

1 Ueber die llemm wig 'smeehanismen fur die Reflex 'that'tglieit dea Ruckonnarksy 1863. Set- schenow und Paschutin, Neue Yersuche, 1865.

8 Exp. sur leu Centres moderators de r action re/fere, 1864.

3 Beitrage zur Lehre von den Ftmctionen der Nervenccntrcn des Frosche*, s. 39, u.s.W. Berlin, 1869.

4 Pflugcr's Archir, x. (1875), 174.

24 W. T. SEDGWICK.

logy, one of which is the remarkable loss of reflex-excitability following the administration of a small dose of quinine to a normal frog.

Except Meihuizen1, whose work I shall review further on, no one, so far as I know, has offered any other explanation of the action of this alkaloid than that it stimulates the so-called centres of Setschenow. Chaperon2 suggested that it probably acted in this way, and believed that he had proved it beyond a doubt by experiments which are bo simple and yet seemingly so conclusive that they have been widely adopted for demonstration purposes.

Thus, if a small dose of some salt of quinine be thrown under the skin of a normal frog, or one from which only the cerebral hemispheres have been removed (and which we may conveniently call an " optic- lobe " frog), a great loss of reflex-excitability occurs. If now we divide the medulla, the excitability returns quickly to the normal. Conversely, if the medulla is divided before the dose is given, no loss of irritability can be detected.

It has also been found that, with large doses, the reflex-irritability may be depressed after a time even in the pithed frog.

Having thus rapidly sketched our present knowledge of the working of this drag, I shall next describe my methods of experimenting ; then will follow a discussion of my work, a few words concerning the case of sodium chloride, and, finally, the application of my results to the general theories of reflex-inhibition.

Methods of Experimenting.

In spite of the objections which have been made to it, Tiirck's method for measuring the reflex-irritability was used throughout. Cyon's objection that, what one measures in such cases is not reflex- excitability, but only the duration of the reflex-time, seems groundless. We know that stimuli in the nervous central organs are cumulative, and if a longer time elapses between the application of acid to the skin and the occurrence of a reflex movement, this can only mean that the stimulation had to attain a greater height before it gave rise to an efferent discharge. The objection has also been raised that, sooner or later, the acid employed must act harmfully upon the bit of skin to which it is again and again applied. It is claimed, too, that the suspen-

1 Pfliiger's jirchiv, vh., 216. 1 Pfliiger's Archil y n., 293.

ACTION OF QUININE ON SPINAL CORD. 25

sion of the frog pats him in such an abnormal position that the results obtained are not trustworthy. These objections, and many more, dis- appear in the light of experience gained by observations made with a careful attention to details.

I have worked only upon frogs. Except in a few cases they were hung up by a large pin (passing through the head between the nares), from either end of a horizontal wooden bar. This bar was supported by having its middle portion nailed to a tall block, so that no other part of the frog's body was in contact with any solid object. A reservoir of water above communicating with a flexible rubber tube closed by a pinch- cock gave abundant and ready means for washing the frogs and keeping them in good order. They were constantly watched, and frequently bathed by immersion in a basin of water lifted from below. This basin of water is also a quick means of removing the acid after the reflex movement has occurred. Draughts of air were found very irritating, and were, therefore, avoided.

Dilute sulphuric acid was employed, and was made by diluting to a litre two c. c. of commercial " pure sulphuric acid." It had a quite distinctly acid taste. The time was marked off by a metronome, beating one hundred strokes a minute. At first the reflex-irritability was esti- mated every ten minutes ; however, if the conditions are good, five minutes is a sufficient interval, and my later observations were made five minutes apart. No comparative experiments were attempted until the record of several consecutive reflexes showed only such variations as would fall within the limits of observation errors.

Perhaps the greatest difficulty met with in using the method of Tiirck is to be sure thatthe toe of the frog dips into the acid equally far every time the reflexes are determined. Carelessness in this respect may produce great variations in a record, and for this reason Meihuizen's plan of holding the frog in the hand is objectionable. Again, the acid must be removed with all possible speed after the reflex movement has taken place.

As I employed it, Turck's method gave satisfactory results; for frogs could usually be kept in good order as long as was needful. A test experiment, in which two frogs had their medullas divided, and soon after were hung up as I have said, showed a record of reflexes which hardly varied for six hours. The irritability was taken every five minutes. So that they were suspended in an abnormal position for nearly six hours ; they had sixty-six applications of dilute acid to the same bit of skin ; these sixty-six stimuli set up as many reflex movements ; yet at

26 W. T. SEDGWICK.

the end of the trial the reflex excitability was precisely the same as at the beginning, and observations ceased only from my own weariness. In the face of such experiments it seems absurd to claim that, under proper precautions, repeated applications of acid of the strength indicated, or repeated demands upon the spinal cord, will lead to serious errors.

It is a matter worthy of close attention, especially in view of the results which I have reached, to consider the form in which quinine shall be given. As Hermann1 points out, the use of acid to dissolve the sulphate is not to be recommended ; for the acid may set up stimuli which will depress the reflexes like other stimulation of sensory nerves. Yet, if sulphate of quinine is to be used at all, acid must be added, for it is little soluble in pure water. For these reasons it seems best to reject the sulphate, and to use the chloride, which is quite soluble in pure water, and weight for weight, contains much more quinine. There is, however, one danger in using this salt which must be borne in mind. If given in doses of a rather concentrated solution it behaves as an irritant. Commonly the drug is injected under the opaque skin of the frog's back. Thinking that less danger of losing any of the dose was incurred by putting it under the abdominal skin (as the frogs sometimes jump about, and by arching the back squeeze out a few drops), I have lately thrown the drug in at a small incision on the abdominal skin near one of the arms. I have noticed, with some surprise, that, after a time, there often appears a large congested area just over the part where most of the solution is lying. m If the aqueous solution of quinine chloride may act in this way it suggests that it should always be dilute ; for if irritating it is quite as objectionable as the acid solution of the sulphate. For ordinary work I have used a freshly made solution, '06 grams of quinine chloride in 10 c. c. of distilled water. This does not appear to irritate ; and using ^ c. c, which is a convenient quantity, a dose of *003 grams is given. The solution of atropia which I employed had '005 grams of the sulphate dissolved in 10 c. c of water ; this gave for each dose of £ c. c. only '00025 grams, yet this minute quantity proved ample.

Quinine Salts.

As has been said above, so far as I know, the'only attempt to explain the action of these salts on any other theory than that they stimulate the so-called centres ofSetschenow has been made by Meihuizen2,

1 Lehrbuch der Experimentellen Toxicologie, s. 366. Berlin, 1874.

2 Pfliiger's Jrchir, vn., 216.

ACTION OF QUININE ON SPINAL CORD. 27

and by him only indirectly. He worked only with frogs whose medullas had been divided, so that these particular centres were out of the question. Still, he advanced a theory for the action of the chloride of quinine on such frogs which, if true there, might also be true perhaps in the entire or optic-lobe frog. It was thought best, therefore, to test his theory. Meihuizen found — and I agree with him in this — that although in the frog whose medulla has been divided small doses of quinine do not seem to affect either the heart-beat or the reflex-excita- bility, large doses do, on the contrary, affect both. They slow the heart-beat and depress the reflex-excitability.

In his other work I have not been able to confirm Meihuizen' s results. Under large doses of quinine I have repeatedly seen the reflex-excitability grow feebler and feebler, till it finally disappeared altogether. In such cases I have almost invariably found the heart still beating, though the circulation in the web-vessels was usually stopped. Meihuizen, on the other hand, finds no loss of reflex- excitability until the heart has wholly stopped beating ; then, he says, the reflexes disappear in from fifteen to thirty minutes, or often even sooner — that is to say, a great loss of reflex-excitability never precedes a cessation of the heart-beat. On this observation he builds his theory, which is, that in frogs with divided medullas quinine depresses the reflexes by producing grave disturbances in the circulation. I can only reconcile my own results with his by supposing that the exposure of the heart which he resorted to in some way causes it to stop sooner than it otherwise would. Different as the case is from that of the ordinary frog supposed to have inhibition-centres, it might be Jhat in the latter the circulation was affected even when no obvious change was seen ; and, as a consequence, by virtue of these centres, quickly depressed the reflexes of the spinal cord. Experiments were therefore begun both with quinine and with sodium chloride, in order to settle the point upon frogs having the so-called centres ofSetschenow. The heart having been exposed in an optic-lobe frog, and a crystal of sodium chloride laid on the cut ends of the thalami, no change in the heart- beat is seen for a short time ; very soon, however, the heart beats slower, becomes dilated, and stops in diastole, with all the phenomena of vagus-inhibition. Almost at the same time convulsions usually begin, and when they are over the heart is found beating again. If the vagi are cut beforehand the heart cannot be stopped in this way ; and so, too, if a minute dose of atropia is given before beginning the experiment it always fails; hence we are probably safe in concluding that the phe-

28 W. T. SEDGWICK.

nomenon is due to vagus-inhibition of the heart-beat, brought about by stimulation of the thalami with sodium chloride. This is a fact of some interest, perhaps. So far, support seemed likely to be given to the theory of Meihuizen. Accordingly, the work upon quinine chloride was begun with special interest, for I did not then know that quinine forbids vagus-inhibition. I soon found, however, that in the entire or optic-lobe frog the heart was not stopped in the same way by small doses of quinine. Moreover, a dose large enough to slow the heart-beat, or to stop it, continues its effect even after that organ has been separated from its extrinsic nerves. Clearly, the cases of quinine and sodium chloride are very unlike, so far as the heart is concerned. I next pro- ceeded to estimate directly the influence upon the reflexes of profound disturbance of the circulation. The reflex-time in frogs with divided medullas having been carefully recorded and found fairly constant, the heart was exposed, and a ligature passed tightly around it, so that all circulation stopped at once. This experiment seemed to show that in no case did the reflex-time change much within half an hour ; and this, it will be remembered, was the extreme period during which, according to Meihuizen, the reflexes lingered after total stoppage of the heart- beat by quinine. Table I. records some experiments made in April on frogs in good order, and under the same conditions. All were tested at the same time, the animals being hung up side by side, and observed one after the other at equal intervals. When it is recollected that, although the incision to expose the heart does not perceptibly affect the reflex-time, ligaturing-off the heart is a more profound operation, the moderate variations which the records indicate may perhaps be well accounted for. On the average, about forty minutes elapsed before the reflex-irritability suffered any great change ; even then the reflexes seemed to fail rather from stiffening of the muscles than from any change in the nervous elements. From the fact which these experiments seem to prove, that a total stoppage of the oirculation has less rapid effect upon the reflexes than even large doses of quinine, we must conclude that quinine does not act primarily upon reflex-excitability by diminish- ing the blood-flow.

Experiment 1.

The observations were made ten minutes apart. Frogs A, B, C, D, E, F, with heart ligatured, show the effect of a total stoppage of circu- lation upon reflex-irritability : their medullas had been divided one

ACTION OF QUININE ON SPINAL CORD.

29

hour before experiments began. E was an optic-lobe frog whose hemi- spheres had been removed several hours before. Frogs G, H, and Z give an opportunity for comparing the effect of large doses of quinine with a complete stoppage of circulation- Z had a dilute, and G and H had a concentrated, dose of quinine.

Table I.

u

Fboo

Faoo

Pmoo

FRO0

Fboo

Fboo

Fboo

Faoo

Fboo

Tra.

A.

B.

C.

D.

E.

F.

O.

H.

Z.

BEMARKS.

1

10.40

10

8

3

8

8

5

6

6

5

2

10.50

5

8

3

4

9

6

6

4

6

u 50+ " means that

3

11.00

6

4

2

3

8

5

5

4

5

the metronome beat over 50 times, and no

4

11.10

5

5

3

4

9

5

5

4

6

reflex movement was

5

11.20

Heart

Heart

Heart

Heart

Heart

Heart

♦

♦

+

seen.

tied.

tied.

tied.

tied.

tied.

tied

Q

Q

Q

6

11.30

8

10

3

6

10

5

10

9

4

The ligatures were

7

11.40

7

7

4

7

17

5

13

9

5

put on lust as soon as the observations given under- 11.10

8

11.50

7

11

4

7

15

6

50 +

50 +

6

9

12.00

9

7

6

7

26

8

50 +

50 +

7

were over, although the Table shows 11.20

10

12.10

19

8

9?

50 +

50 +

50 +

etc.

etc.

9

as the real time* The

11

12.20

50 +

10

50 +

50 +

50 +

50 +

50 +

average time which elapsed between the

12

12.30

50 +

11

50 +

etc.

etc.

etc.

50 +

application of the ligature and the loss

13

12.40

etc.

12?

etc.

etc.

of all reflex indicated

14

12.50

50 +

by the second 50+ was not less than 46

15

1.00

50 +

minutes.

16

1.10

etc.

Having in mind the remarkable inhibition of the heart-beat by sodium chloride applied to the mid-brain of the frog, which seems to point clearly to a distinct efferent impulse proceeding from the stimulated part, and recollecting the various phenomena of simultaneous stimulation, such as the diminished irritability in one leg when the sciatic nerve of the other is stimulated by a strong electric current, it is not difficult to suppose that all the reflex-inhibitions produced by applying sodium chloride to the nervous apparatus of the frog are special cases of simultaneous stimulation.

Turning next to quinine, and attempting to apply, in this case, the same theory, our attention is at once drawn to the important fact that quinine has a decided effect upon the heart itself. Something is certainly going on here, for the heart beats slowly under a moderate dose and ceases to beat altogether under a large one.

If counter nervous stimulation occurs in this organ it must be

30 W. T. SEDGWICK.

through the vagus nerve. If this acts as the afferent nerve, whose stimulation is to depress reflex-excitability, then division of the medulla below the nerve must forbid that depression, as it does. By reviewing the subject and by this train of thought I was led to believe that such a theory would account well for the facts and do away with the necessity for supposing the existence, in this case, of special inhibition centres ; it would be this : quinine salts acting upon the nervous network of the heart, stimulate the vagus nerve, and so depress general reflex-irritability in a way similar to that in which electrical stimulation of one sciatic nerve may depress the reflexes in the other leg.

This theory accounts well for facts which have long been thoroughly established, and, if true, need meet with little objection, for its depressing effects upon the reflex-excitability of the cord are only simplified and placed alongside of many other cases of simultaneous stimulation which are unquestioned. The return of that excitability after division of the medulla is accounted for, since the source of the depression — the stimulated nerve — is no longer connected with the cord ; and, con- versely, if the medulla is divided beforehand no depression can occur for the same reason. Moreover, the effects of small and large doses upon frogs with divided medulla should be, as they are, totally unlike the effects of the same doses upon normal or optic-lobe frogs.

If my theory is true, section of the vagus nerves ought to be, so far as the reflexes are concerned, equivalent to dividing the medulla. Accordingly I divided both vagi close to the medulla, but the results were not constant. Owing to paralysis of the laryngeal muscles the frogs no longer breathed normally and always bore the marks of a too severe operation. No absolutely contradictor}* results were obtained; still sometimes, after quinine-giving, the reflexes fell, but as it seemed rather from general exhaustion of the animal, and in others the reflexes continued as if no quinine had been given. Division of the visceral branches of the vagi below the origin of the laryngeal was a less severe operation, and was correspondingly more successful. A great trouble in this mode of experimenting is that a very considerable number of the frogs after the operation swell up enormously and utterly fail to expire. The phenomenon is described by Heinemann, and frogs which show it are no longer available for experiments upon reflex-irritability. Then, too, even of those which do not seem affected in that way, it may be true that there is something going on which, while it is not conspicuous, may, notwithstanding, affect the reflexes. Those frogs which showed no gigns of Heinemann' s phenomenon gave very fair results.

ACTION OF QUININE ON SPINAL CORD. 81

Exp. 2, see Table II., records some of these results and affords an opportunity for comparing them with the effects of similar doses upon the normal frog. It should not be forgotten that an animal which has undergone a severe operation cannot be expected to retain irritability so long as an animal unoperated upon.

Experiment 2.

The observations took place five minutes apart. For convenience they are arranged as if they were made simultaneously. They repre- sent some of the best cases for the theory.

A, B, C, D had had the visceral branches of their vagi divided below . the origin of the laryngeal several hours before.

E was an optic-lobe frog. F, G, and H had undergone no operation.

The experiments occurred in April and May, 1880, and the weather was favourable for the work. Frogs were chosen with special reference to the apparent absence of Heinemann's phenomenon.

The results thus far obtained, though very encouraging, were not perfectly satisfactory. It was therefore decided to make use of atropia, in the hope that, since it is believed to paralyse the inhibitory vagus- endings in the heart, it might also paralyse the ends of the afferent fibres, and so prevent the action of quinine, which, the theory supposes, stimulates those endings. This test proved perfectly satisfactory. Table III. shows several cases, which may be compared with others taken at the same time when no atropia was given. They are representative examples. The dose of sulphate of atropia ("00025 grams) is very small, but after it has been given the usual amount of quinine seems to have no effect at all.

It will be remarked that the small quantity of atropia does not itself affect the reflexes. This I have proved by separate experiments, see Exp. 3, Table III.

82

W. T. SEDGWICK,

•

•

Table II.

u

FftooA

FbooB.

PmooC

FrooD

1

i

oi

Tina.

FbooB

. FmooF

FbooG

. FbooH

REMARKS

^n

y^"

'S

r

With rafl divided.

11

6

i

3.10

10

6

8

10

10

10

2

3.15

9

7

6

11

9

12

10

6

3

8.20

8

6

7

9

8

11

11

5

4

3.25

8

5

7

5

7

9

9

6

5

3.80

7

6

6

4

7

10

10

5

6

3.35 3.40 3.45

8

+

Q

6

7

4

8

11

9

5

For the signi-

7

+

Q

Q

Q

Q

+

Q

Q

Q

ficance of "60+"

8

22

6

—

4

11

24

—

11

see Table I.

9

3.50

9

7

8

3

11

13

10

10

10

8.55

8

6

7

3

9

16

9

11

11

4.00

11

6

9

4

7

15

13

12

12

4.05

10

6

9

3

8

25

20

10

13

4.10 4.15

12 10

9 11

9 11

4

15 14

40

16 17

12 18

"M. d." means

14

More.

M. d.

"medulla di-

4.20

8

11

^â– n_

Q

5

14

23

28

vided."

15

16

4.25

9

9

—

5

28

—

46

17

4.30

—

10

—

5

50 +

—

—

etc.

18

4.85

4.40

4.45 4.50

—

14

12

12 12

—

4

4

4 5

50 +

20

26

15 18

—

â– 

19

M.d.

The dash is

20 21

21

used instead of

22

4.55 5.00

12 29

More.

♦ Q

18 18

18 13

•

the words, "No observation."

23

8

24

5.05 5.10 5.15

80

10 12 11

13

—

25

M.d.

26

—

D had, in all,

27

28

5.20 5.25

No

11 10

—

•^—

three large doses

29

5.30

reflex.

13

—

of quinine.

80

5.85

37

31

5.40 !

50 +

82 i

5.45 :

5.50 ,

i

i

50 +

•

83

Deed.

'

ACTION OF QUININE ON SPINAL CORD. S3

If proof for my theory depended solely upon, the action of atropia, it might properly be argued that we know too little of the action of this drug to base upon its effects any explanation of the working of quinine ; but when taken in connection with the effects produced by vagus-section, it becomes a valuable ally for the theory. Owing to the sudden advent of warm weather I have made but a single experiment to see if atropin was a general paralyser of inhibitory fibres. An optic- lobe frog, to which a large dose of atropia had been given, showed the ordinary loss of reflex-irritability when his lobes were stimulated with salt. Moreover, it is hardly possible that the small dose which I have used could prevent general reflex-inhibition.

These experiments seem to me to show that quinine salts, when given to the normal or optic-lobe frog in small doses, depress the reflex- excitability by stimulating the vagus nerve through its endings in the heart. It is not unlikely that the pulmonary and gastric endings may also be influenced, but I have no proof of their action.

If my work shall be confirmed, it must be admitted that in the frog with divided medulla we have a different problem to solve. Small doses are here ineffectual ; and when we recollect that quinine is a proto- plasmic poison, and in large or concentrated doses may become an irritant, several possibilities arise. Quinine may poison the cord directly, or have some other equally obscure action ; but from some experiments which I have begun but have not yet completed, it is possible that the depression in these cases is due to intense simultaneous stimulation ; the irritating quinine solution being a stimulus comparable to the electric stimulus applied to a sciatic nerve, and, like that, affecting materially the general reflex-excitability. That it acts more feebly in case the brain and great nerve-centres are gone is to be expected ; it has less to work with and upon.

Sodium Chloride.

My work upon the behaviour of this substance has not perhaps gone beyond that of other observers. Their accepted results I have been able to confirm in most cases. Herzen's observation that stimulation of the cord could cause a depression of excitability I have fully confirmed by dividing the medulla, estimating the reflex-time before and after placing salt upon the section. On cutting across the cord again below

•3

W. T. SEDGWICK.

Experiment 3.

Observations occurred five urinates apart. Frogs A, B, C, D, E show that atropin does not in such doses affect the reflexes ; also that after atropin-giving quinine is ineffectual. F, Q, H, I show the effect of the same doses of quinine when no atropin has been given. In no case after atropin-giving have I seen quinine have its ordinary effect.

h

-â– 

M.A.F.1

Fin C.I Tmoo D-fivoE

^gajg^g^.,

.„.,„

£8

«J^.,

W-J^Wb.

***>*-«■ '

1

9.25

9 7

7

—

8

7

_

7

10 1

2

s.ao

9 4

5

'â– >

9

8

9

9

9 '

8

9.35

10

4

4

9

9

7

8

7

10

4

9.40

7

3

8

8

10

9

6

8

10 |

5

9.45

7

B

4

n

9

9

7

9

10

For the nlgnMcmnrt

+

(

t

â– m

va ' an

â– tm

6

9.50 9.56

A. 80

A Ml,

ABO

ISO,

A BO

ia

irJt*

J of -IO+»Md tW diuh, «<e T»blM I.

7

8

3

6

9

10

ii

14

35

17 sad It.

8

10.00

8

4

6

7

9

20

[3

48

16

9

10.05

8

4

4

8

10

18

U

M +

1* i

10

10.10

a

6

8

6

10

24

16

50+

21

11

10.15

8

4

4

7

9

25

15

etc

16

Owing to •miitikt

H bad a double flow.

12

10.20 10.25

$a.

5«

$a.

$CL

to.

27

87

20 17

18 16

13

9

•!

:>

—

9

1-1

10.30

8

7

5

7

10

50+

'•(> +

A 80*1 Frog V shown bow [

15

10.35

5

8

6

9

9

50+

50+

-iy tbe amrags eflset o(

16 17

10.40 10.45

6 7

7 9

4

8 8

10

a

etc.

etc

13 25

UU1 1'IWb |nnj OT quinine chloride » I bavo freqnentlj ob-

18

10.50

6

10

6

8

*

25

icrvedlt.

19

10.55

9

10

7

12

:"::;:;.

Lkm

SO

11.00

9

10

6

11

y

ST"l

21

11.05

9

6

5

—

8

50 + !

22

11.10

9

7

4

8

a

j0+ FroB 1'* record

28

11.15

8

7

ft

10

0

etc. i ^? th" *" dM

24 2ft

11.20 11.25

7

8

etc.

4

etc.

7 6

10

(â– OWiiJ of atropin â– tors tbe reBBi trrlu-

26

11.30

8

6

11

billtT-

27

11.35

7

0

12

28

11.40

6

etc.

10

i

29

11.45

7

I'

30

11.50

etc.

Etc

ACTION OF QUININE ON SPINAL CORD. 85

this point the reflexes may often be restored; they may then be again depressed by salt and restored by section.

I wish merely to call attention to the evidences of simultaneous stimulation in the case of sodium chloride, as bearing upon theory. These evidences are, first, the fact that the heart may be stopped by applying salt to the thalami; second, that at about the same time convulsions occur ; and, third, these are not due to stimulation of the so-called " convulsive centre," since they occur almost as well if the salt is laid upon the cut cord from which the medulla has been removed. These facts, if they show anything, show that the salt may act as a direct stimulus of considerable power.

Theoretical Considerations.

I have not overlooked the difficulties which seem to arise from the strange behaviour of atropia towards quinine depression of reflex- excitability. It is not easy to understand how two drugs which have, apparently, the same effect upon the inhibitory function of the vagus shall nevertheless .act precisely unlike upon the vagus nerve in respect to reflex depression. At first sight we can only escape by saying that it (quinine) acts as a paralyser of inhibitory endings and as an excitant of afferent endings of the vagus nerve, while atropin paralyses both. This hypothesis, however, assumes a distribution of function in the vagus fibres which we are hardly justified in making. In view of the discovery by Prof. H. Newell Martin1, that special reflexes may be inhibited by the stimulation of the central ends of efferent fibres, we may have to change all our ideas of reflex-inhibition, and it may be that quinine merely stimulates the ends of the efferent cardio-inhibitory fibres, and these act back in the centres.

Since atropin is known to paralyse the peripheral organs of the cardio-inhibitory fibres, we would then get an explanation of the fact that after its administration small doses of quinine are without effect on the reflexes. Otherwise it would appear that we must assume that atropin paralyses also the ending of afferent vagus fibres in the heart,

1 Johns Hopkins, University Circular, May, 188Q. A preliminary account of some experiments tending to prove the existence of a new function in the anterior roots of the spinal nerres.

86 W. T. SEDGWICK.

which are stimulated in the organ under the influence of quinine and depress the reflexes.

The slowing of the heart under quinine, and at the same time the loss of cardiac inhibition on direct vagus stimulation, show that the cardiac action of the drug still needs much more investigation.

If the statement which was made at the outset, that the theory of Setschenowis better sustained by quinine than almost anything else, is true, then it must be granted that that theory now rests on a weak support. If my results secure confirmation, quinine does not depress the reflexes by the mediation of any special inhibitory centres. Moreover, it seems to me that all the phenomena found in using common salt to demonstrate the existence of these centres may be better explained by looking at them as particular cases of simultaneous stimulation, com- parable to the general inhibition of reflexes accompanying the powerful stimulation of a sensory nerve.

Sodium chloride, although its first cause, has for some years been a stumbling-block in the way of the theory of Setschenow, while quinine has been one of its most important supports. Goltz's theory, on the contrary, has been made more probable by the action of salt, and has hardly accounted for the effect of quinine. It will be seen that the results of my work support Goltz and render highly improbable the theory of Setschenow.

The general results of this paper may be stated thus : —

1. Quinine salts in small doses seem to depress the reflex-excitability of the cord by stimulation of the vagus nerve ; mainly through its end- ings in the heart.

2. This places the quinine action alongside other stimuli of sensory nerves, and explains it action by saying that it is a special case of reflex depression by simultaneous stimulation.

3. Goltz's theory is supported, and that of Setschenow much weakened by these phenomena.

4. Reflex depression under quinine salts, in the pithed frog, is a case wholly different from the same depression in the entire frog. Larger doses are required, and the drug possibly acts as a direct poison on the cord.

It is not unlikely that other drugs may act like quinine upon the

ACTION OF QUININE ON SPINAL CORD. 37

•

reflexes. I propose to continue my work and shall especially examine digitalis, and others which act upon the heart.

The materials for this paper were accumulated in the Biological laboratory of the Johns Hopkins University, in charge of Prof. H. Newell Martin. I am glad of an opportunity to express my feeling of deep indebtedness to him for the constant encouragement and wise counsel with which he has favoured me.

THE EARLY DEVELOPMENT OP THE WOLFF- IAN BODY IN AMBLYSTOMA PUNCTATUM.

By SAMUEL F. CLARKE, Ph. D., Late Fellow and Assistant in Biology, Johns Hopkins University. With Plates I, II and III.

The first indication of the urinogenital system in Aniblystoraa is found at the period of development represented in Figure 1. At this stage, as 6een in cross sections, Figures 4iV to 13JV, the mesoderm extends entirely around the body forming a two-celled lamella. In the region which is to become the intermediate cell mass, both layers of mesoderm are much enlarged, see Figures 4N to 12 N. This enlargement of the mesoderm is produced by a growth of and not a multiplication of the cells, as is seen in the Figures of series "N" This beginning of the Wolffian blastema was found extending through a few sections only in a consecutive series. In the next later stage from which a series was obtained, Figure 2, the somatopleure cells of the blastema have become very much larger than those of the splanchnopleure ; the former divide transversely and then become differentiated from the rest of the mesoderm by a definite outline. This blastema now consists of a solid mass or rod of cells lying just ventral to the lateral plates, bounded on the inside by the splanchnopleure, on the outside by the epiderm and formed from the outer layer of mesoderm. At its anterior end through six or seven sections it is of considerable size, then it suddenly becomes much smaller and continues without change through ten or twelve sections farther backward. In the next succeeding series of sections, taken from a specimen repre- sented in Figure 40, one finds that the body cavity is beginning to be formed and the Wolffian blastema is seen to be entirely in the somatopleure; no anterior opening has yet been formed in the segmental duct, as Balfour has called this structure in the Elasmo- branchs, as is demonstrated by the first section. The next two sections show that a lumen is being formed within the previously solid rod, while the three sections following these two indicate a partial differentiation of the blastema into a dorsal and ventral part. After one or two sections more, the dorsal portion termi- nates and the ventral part continues posteriorly as a solid rod. 4 • 39

40 8. F. CLARKE.

The next or fourth series are from an embryo represented in Figure 41 Y. In this stage one finds from the sections that the dorsal duct now opens anteriorly into the body-cavity ; the split has worked its way forward to the anterior end of the blastema, separating the anterior end into two quite separate parts or ducts, each with a lumen, but the ventral one ends blindly while the dorsal one communicates with the body-cavity. Below the ventral duct is a small solid rod of cells which was, I believe, not formed from the blastema. In section number 37 Y of this series the dorsal and ventral ducts have united into one which possesses a single large lumen. The next succeeding section shows this single duct opening into the body-cavity.

The Wolffian body then, arises from the outer layer of the mesoderm as a solid rod of cells, and is at first largest anteriorly ; a split then occurs in the larger portion which begins at the pos- terior end of the smaller part and travels anteriorly, and at this time a lumen has appeared in the anterior end of the blastema ; finally, the split reaches the anterior end thus dividing that portion into two ducts; the lumen is extending itself backward, a small rod of cells has been formed below the anterior end of the ventral duct, the dorsal and ventral ducts are united at one point, and a second opening into the body-cavity from the dorsal duct has been made. This method of development seems to be quite different from that in any allied forms in which the development has been worked out. As it is most like that of the Elasmo- branchs, I will add a brief account of the development of the urinogenital system in the latter group as given by Balfour. It first makes its appearance as a solid knob of cells springing from the intermediate cell mass. From this knob a solid column of cells grows backwards to the level of the anus. The knob then acquires an opening into the body-cavity which is continuous with a lumen that makes its appearance in the rod of cells. Solid out- growths of the intermediate cell mass then appear which soou become hollow and open into the body-cavity. Their blind ends curl obliquely backwards and open into the segmental duct. After all this has taken place the segmental duct splits longi- tudinally into two ducts in the female, and into one duct and parts of another in the male.

In comparing this with Amblystoma, one notices that the origin of the primitive rod of cells is very similar in both, they agree

AMBLYSTOMA PUNGTATUM. 41

in the anterior opening into the body-cavity and in the lumen appearing anteriorly and working its way backward. Beyond these points they are unlike. The splitting of the segmental duct in Amblystoma takes place at a much earlier period and proceeds in a different way. The second opening into the body-cavity is also peculiar to Amblystoma as is the small rod of cells lying ventral to the two tubes which are derived from the blastema. It is possible, however, that this small rod is not a part of the urino- genital system; and this second opening into the body-cavity is probably the beginning of the first segmental tube.

It is a matter of great regret to me that I have not sufficiently complete results to allow of any theoretical considerations, and I have concluded to publish this short descriptive paper because there is enough to show that the method of development of the Urinogenital system in Amblystoma is quite different from that of allied forms, and indicates a promising field of work, if the sections can be obtained. I have worked many months to obtain the few results here recorded, so difficult is it to obtain workable material. Many thousands of sections have been prepared and mounted, nearly all of which from one cause or another are valueless; many are utterly worthless, while a large number, though partly good, are not reliable. I have had the best results with Picric acid specimens, and find that they work better a few days after they have been transferred to absolute Alcohol, than when longer kept.

EXPLANATION OF PLATES.

The figures are numbered from 1 to 41 and the different series of

sections are indicated by letters annexed to the numbers of the figures.

All of the figures were outlined with the aid of the camera lucida.

PLATE I.

Figure 1. — A side view of the specimen from which the series of

sections marked "N" were obtained, nc, neural canal; e, eye ; t, throat ; a, future position of cloaca. Mag- nified six diameters.

Figure 2. — A side view of the specimen from which the series of

sections marked "P " were made, e, eye ; nib, mid-

42 S. F. CLARKE.

Figure 2. — Continued.

brain; bn, branchial lobe; ba, brachial lobe, from which the anterior limb is developed; pr, protover- tebrae. Enlarged six diameters.

Figure 3. — A diagrammatic figure of the developing Wolffian body

of Amblystoma made from series "Y." pp, body- cavity; 61, the dorsal duct, opening anteriorly into the body- cavity ; x, its second opening into the body- cavity; 62, the ventral duct which unites with the dorsal duct just in front of the second opening of the latter; 63, the small rod of cells which appears just beneath the ventral of the two large ducts.

Figure 4N. — A cross-section through the body at the anterior end of

that enlarged portion of the mesoderm from which the Wolffian blastema is formed. The hypoblast cells are very large and filled with very coarsely granular proto- plasm ; ac, the alimentary canal ; nt, the notochord which appears to be formed from the hypoblast ; w>6, the enlarged part of the mesoderm from which the Wolffian blastema is formed. The mesoblast at this stage extends entirely around the body, forming a two- celled lamella, ep, epiblast.

Figures 4 N to 8 N, are consecutive and show that this enlarged area

of mesoderm extends through these five sections without any marked change.

PLATE II.

Figure 9 N. — This is not the next section to 8 N, but is next but one.

The enlarged portion of mesoderm wbt still per- sists.

Figure 10^. — This represents the next section but one to Figure 9 N,

and shows no marked change.

Figure ION, to 13 N, are consecutive. Figure 13 indicates the pos- terior termination of the mesoderm marked wb.

Figure 14P, to2lP, are consecutive, and are taken from the speci- men represented in Figure 2. The series- is com- pleted with Figures 22 and 23 on Plate III.

Figure 14 P. — A section through the anterior end of the Wolffian

* blastema, wb.

AMBLY8T0MA PUNCTATUM. 43

Figures 15 P, to 20 P, are essentially alike, showing the Wolffian blas- tema, 6/, extending backward without marked change in size or form.

Figure 21 P. — In this section the blastema, bl, suddenly diminishes in

size.

It will be seen from a comparison of sections, 14 P and 15P, that the Wolffian blastema is found from the outer layer of cells of the mesoderm.

PLATE III.

Figure 22 P, is next but one in the series to 21 P. There is not much

change ; the intermediate cell mass with the blas- tema bl, is more distinctly separated from the pro- tovertebrse.

Figure 23 P. — This is five sections further backward in the series than

22 P, and shows the blastema reduced to a small rod of cells. It occurs in one or two more sections only and then terminates.

Figures 26TFto 32 W, form the third series, and were made from the

specimen represented in Figure 40.

Figure 24 W. — The anterior end of the blastema is shown at bl. The

body-cavity pp, is beginning to be formed.

Figures 25 IT, and 26 IF. — The blastema is larger than in 24 IF, and

the body-cavity is still present.

Figure 27 W. — The blastema is here much enlarged and is being

divided by a median transverse division.

Figure 28 IF — The split is here indicated also, but the upper or dorsal

portion is much the largest. The body-cavity pp, is present but disappears in the next section.

Figure 29 IF. — There are now two distinct ducts, a dorsal bllt aud a

ventral bill.

Figure SOW. — The two ducts are still present but their lumena have

disappeared.

Figure 31 W. — The dorsal duct bll, here terminates while the ventral

one persists.

Figure 32 W. — This is next but one in the series of sections. The now

single rod of cells extends only a few sections farther.

In studying this series "IF" it appears that the blastema in its en- larged anterior part becomes longitudinally divided by a split which starts at the posterior end of the swollen portion aud travels anteriorly.

44 S. F. CLARKE.

Figures 33 Y, to 39 Y, comprise the last series, and were obtained from

an individual shown in Figure 41 Y.

Figure 38 Y. — A section through the anterior end of the developing

Wolffian body ; be, body cavity, into which opens the dorsal duct 61; 62, the ventral duct and 63, a small rod of cells which is found only in this and the fol- lowing section.

Figure 34 Y. — The dorsal duct 6 1, is here distinct from the body cavity,

6c. There is a peculiar collection of cells about the ventral duct which may be a trace of the primitive connection of the dorsal and ventral ducts, the split not being quite completed at this point. There is a small lumen in each of the two ducts. The small ventral rod of cells is also present.

Figure 35 Y. — The dorsal and ventral ducts hold the same relative

positions and have the same characters.

Figure 36 Y — The two ducts have united, forming one large duct

with a large lumen.

Figure 37 Y. — The single duct here opens into the body-cavity.

Figure 38 Y. — The single duct has become a solid rod of cells, and in

this condition stretches away toward the posterior end of the body.

Figure 39 Y. — This is six sections posterior to 39Y, and beyond this

the "rod " does not extend.

Figure 40. — A side view of the individual from which the series of

sections marked "W," were made, e, eye; 6at branchial lobe ; 6n,.brachial lobe; pr, protovertebrae. Enlarged six diameters.

Figure 41 Y. — A side view of the specimen from which series " Y" were

obtained ; r?p, nasal pit ; e, eye ; bal, balancer ; 6n, branchial lobe ; 6a, brachial lobe. Enlarged six diameters.

Figure 3, on Plate I, gives a diagrammatic side view of the develop- ing Wolffian body of Amblystoma constructed from this series of sections marked "Y."

NOTES ON THE FORMATION OP DENTINE AND OP OSSEOUS TISSUE. By CHRISTIAN SIHLER,

M. D., Ph. D., Late Fellow and Assistant in Biology, Johns Hopkins University. With Plate V.

I. Dentine.

There are two views held regarding the formation of dentine : one supported by Waldeyer, in Strieker's Handbook, the other by Rolliker, in his Histology. According to the former all the cells of the tooth pulp are used up in the formation and are actively engaged in the production of dentine. According to the second view the odontoblasts only are the elements whose function it is to deposit dentine. Waldeyer believes that osseous tissue and enamel develop in quite an analogous way.

I shall now bring forward the observations which I have made on the tissues coming into play in the process, and then consider which view they support.

(1). Cracking with a vice the incisor of a calf, or splitting the root with a knife, one finds that the pulp is removed from the dentine very easily indeed; great difficulty is often experienced in keeping it adherent to the dentine in order to make sections through pulp and dentine, both remaining in their natural position with reference to each other. This behavior of the pulp towards the dentine is in striking contrast to that of the pericementum towards the ceraentum, and seems to me to throw some light on the difference in their respective modes of growth. Although this fact is one readily observable without the microscope it seems not less important on that account.

(2). Before enumerating the facts brought out by the microscope, I shortly describe the method. The materials used were, princi- pally, the incisors of the calf, the roots of which were split longi- tudinally that the stainiug fluid might have access to all the parts, including the dentinal canals; and care was taken to disturb the relation between the pulp and dentine as little as possible. In the staining fluid, Beale's carmine, the teeth remained, until the pulp- cells were deeply stained; after washing with acidulated glycerine, they were transferred to dilute alcohol, from this into strong alcohol, and then allowed to dry, the pulp applying itself closely —

45

46 C. SIHLER.

in some parts at least — to the dentine. Sections were then made with a hard and fine scalpel, through all the parts, pericementum, cementuni, dentine and pulp, or through parts of these layers, as was desired. The sections were then treated with glycerine and acetic acid, which swells them out and brings them back to their natural condition.

Figure 1, Plate V, shows such a section passing through the root, a, pulp — near the dentine the darker red shows that the cells there are either large or more numerous. 6, the pink zone, the newest layer of dentine which is not yet ossified, c, the fully formed dentine. /, the pericementum. e} the uncalcified cemen- tum (again a pink zone), rf, the calcified cementum.

This drawing is intended to show only the general arrangement of the parts, and is but little magnified.

Figure 2, Plate V, more highly magnified, shows the fully formed dentine and the adjoining soft tissues where the growth of the dentine must be in progress. We observe here — a, the calci- fied deutine. 6, the uncalcified dentine, (the pink zone already mentioned). The newly laid down semi-solid material absorbs some of the carmine, but is not stained as deeply as the protoplasm of the cells. Next comes a layer of large and long cells, reminding one of columnar epithelial cells, with a dark red nucleus situated generally towards the blunt end of the cells which is directed towards the pulp. There has never come such an odontoblast under my notice with more than one nucleus, d, the pulp proper showing oval and roundish masses of protoplasm imbedded in formed matter of a finely fibrillated character.

(4). The elements making the pulp can readily be examined, by teasing and scraping a pulp which, after having been removed, has been kept in bichromate of potass solution. Figure 4, Plate V, shows such cells. They form very irregular, Branched, and varied figures, their processes evidently running out into and continuous with the fibrous network of the pulp. The naked eye shows, and this must be borne in mind, that the pulp is exceedingly vascular, and, upon teasing, larger vessels with unstriated muscular fibres, and smaller ones richly nucleated, are observed pervading the whole pulp.

(5). The odontoblasts in a very natural condition can be pro- cured by scraping the freshy formed dentine or walls of the pulp cavity, after removal of the pulp. For when the pulp is drawn

DENTINE AND OSSEOUS TISSUE. 47

out of the tooth, the line of separation takes place as a rule between the odontoblasts and the pulp, the former remaining in connection with the dentine.

Figure 5, Plate V, gives a number of forms, not unfrequently observed. A very typical one is a, where we observe a large nucleus near the inner rounded end, while the other extremity of the cell looks squarely cut off, with a process or fibres attached to one corner. In other odontoblasts a large process runs from the outer extremity of the odontoblast, evidently pulled out from a dentinal canal, (and as we shall notice afterwards, continuous with the dentinal tubule and its contents), I have never observed two odontoblasts joined end to end.

(6). In a well-stained specimen not only the odontoblasts are of a red color but also the contents of the dentinal canals ; just as in the cornea we have the nucleus, the body of the cell, and its pro- cesses by which the protoplasm of the different cells is put in connection, so in the living and growing dentine we have the nucleus in the odontoblast, the body of the cell and its processes permeating the dentine.

(7). If a section is made with a scalpel through the root of the tooth, or more accurately through the dentine with the odonto- blasts attached and in place, and such a section is treated with strong hydrochloric acid, the ground substance of the dentine is destroyed, and there are left behind the cells and their main processes, corresponding to the tubules. I may just recall here, that when dead and dry dentine which has been boiled, and where the protoplasm has been destroyed, is treated with strong hydro- chloric acid, the tubules remain behind. By taking these two observations together, we see that the odontoblast and the dentinal tubule with its contents are one thing. (It is hardly necessary to mention that the former observation has been made also before by Lent, and the latter by every body.) Jt is found further that the odontoblasts do not separate readily laterally but are evidently united one with another along their sides, although the con- necting fibrils or tubules cannot be distinguished; but the short processes apparent on the isolated odontoblasts seem to be these connecting threads.

(8). Treating a section prepared as described under (2) with dilute hydrochloric acid and pressing it with a coverglass one often succeeds in separating the odontoblasts — adhering then to 5

48 C. SIHLER.

the pulp — from the dentine, in such a way that fibres are seen across the interval between dentine and soft parts; and in favor- able specimens it can be made out that these threads corres[>ond to the large and thick external processes of the odontoblast de- scribed above. That they can undergo so much stretching, as they do, without tearing, seems to show that they are not protoplasm pure and simple, but that their outer part is a thin dense envelope, in fact the dentinal tubule (or Neumann's sheath) of the dead and dry dentine. I think some authors confound this elastic tubule with its protoplasmic contents.

Taking all the observations together we would have then — the vascular pulp with its branching cells, the processes of which have no definite arrangement but pass into a fibrous texture, the meshes of which are filled up with a mucous ground substance; and out- side the vascular pulp the odontoblasts, the end processes of which pass into the walls of the dentinal canal, i. e., the dentinal tubule. The odontoblasts themselves staining readily and carrying a large nucleus are evidently in great nutritive activity, and their proto- plasm is continuous with that lying in the dentinal tubule. The newly formed dentine we find as an apparently homogeneous, semi- transparent coating, covering the calcified dentine; it is not found between the odontoblasts, but only at their outer extremities.

Now taking the case before us, i. e., a root of a tooth which is growing, and waiving at present the question as to the method of the first beginning of the growth of dentine, in what way does the increase in the thickness of the dentine take place?

Taking all the facts into consideration, the most probable view seems to be this: The odontoblasts absorb from the pulp the necessary nutriment and form a secretion ; they pour this out in such a way that the portion produced by the single cell cannot be dis- tinguished from that produced by its neighbors, and this new layer stains pink if the lime-salts have not yet been deposited in it. As the odontoblasts form this secretion on their outer ends, they move necessarily inward, and at the same time spin 'in their wake the dentinal tubule. The side branches of the main tube correspond to the lateral processes (spoken of above) holding the cells together. Of course we must conceive that new lateral processes are con- tinually being formed by the soft anterior part of the odontoblast as this moves and grows inward. In moving onward thus, the odontoblasts must of course remove the pulp, and we may imagine

DENTINE AND OSSEOUS TISSUE. 49

this to be done in two ways: either the odontoblasts being very active in their nutrition take away the pabulum from the other pulp-cells — the latter shrivelling and disappearing, or the odonto- blasts live on the pulp-cells directly just as the tooth-sac of the second tooth absorbs the roots of the deciduous tooth.

Waldeyer has come to different conclusions with reference to this process. In Strieker's Handbook, (p. 337), we find the following passage: " Whilst the peripheric portions of the odontoblasts con- tinually undergo metamorphosis, with disappearance of their nuclei, into a gelatinous matrix which subsequently undergoes calcifica- tion, their centric portions penetrate the hardened mass in the form of longer or shorter threads, and represent the first rudiment of the dental fibres. The lateral processes of the odontoblasts occa- sion the numerous anastomoses of the dental fibres or of the dental tubule. Every odontoblast communicates with the nipre deeply situated and successively enlarging cells of the young pulp, by means of its pulp process, so that when an odontoblast is calcified up to the base of the fibre another occurs in its place without any interruption to the continuity of the fibre. Hence every dental tubuje with its anastomoses must be regarded as formed of several continuous odontoblasts. The layers of matrix immediately sur- rounding the fibres undergo conversion, as appears from their chemical character, into elastic tissue and form the dental sheaths of Neumann. It has not yet been ascertained whether they also undergo calcification. Thus it appears, that the dentine with all its constituents proceeds from odontoblasts that have become metamorphosed in their form and chemical composition. "

There seem to be several objections to this view.

In the first place if we do what Waldeyer asks us and imagine the process to take place as he describes it, let every odontoblast have a pulp-process analogous to its dentinal process — (which I have failed to find and others fail to mention) — imagine the numerous nuclei to disappear, the rearrangement of the eel I -processes of the pulp-cells into the tubule-network of the dentine, the metamorphosis of the bodies of the pulp-cells into dentinal matrix, having done that, would we then after all have such a tissue as we find dentine to be? No, we would have a hard tissue, with cauals, (but could they have the regularity of the dentinal tubules?) and supplied very richly with bloodvessels something like very vascular bone. Wal- deyer quite forgets to dispose of his vessels and they are present in

50 C. SIHLER.

•

great abundance. Nor would they disappear by mere conversion of the pulp-cells iuto gelatinous matrix and Neumann's sheaths.

Further, if such a direct transformation of the pulp took place one might expect to find evidences of the former pulp-structure in the final dentine ; this has so far not been demonstrated.

In the third place, if the outgrowths of the dentine took place ought we not to see the deposition of dentine between the odon- toblasts along their sides, and ought we not to find dwindling odontoblasts or evidences of disappearance of their nuclei, as well as pulp-cells which were being changed into odontoblasts to take their place; finally, ought there be that tendency to separation between odontoblasts and the remainder of the pulp which cer- tainly exists?

What we really find is the newly produced dentine deposited as a homogeneous coating on the calcified dentine, without any evidence whatever of one portion being the metamorphosed odon- toblast and of the other being another chauged cell.

If it could however be shown that there was a very intimate union between the odontoblasts and pulp, and if the odontoblasts which Waldeyer figures were the typical ones, this would speak in favor of his view.

It is of course difficult to give convincing proof of such processes as we cannot watch during their occurrence; all we can see is the machine at rest. It seems however to me that there are more difficulties connected with Waldeyer's than with Kolliker's theory.

There is one point however in Kolliker's description with which I cannot agree, namely, the formation of the side tubules. He says: "The finer processes of the dentinal fibril are not present when the dentine is first formed and must be looked upon as secondary formations, just as those of the lacunae of bone."

This point will be better discussed when the formation of the osseous tissue is under consideration.

II. Osseous Tissue.

In the investigations of the formation of osseous tissue, the long bones of kittens, newly born and of more advanced age, were chosen, and the calf's teeth illustrating the formation of cementum, which I include here under bone. Embryonic bones of sheep

DENTINE AND OSSEOUS TISSUE. 51

and calves were also used, and the tissues were treated essentially as were the teeth for the study of the development of dentine.

Figure 5, Plate V, represents a longitudinal section of a kitten's femur, passiug through bone and the outside periosteum. The following are the points that are to be distinguished and taken into consideration, (a) is the fully developed bone substance; in it we recognize the lacunae and canal iculi. The latter (the canal iculi) we cannot see in the pink zone (6) although two lacunae happen to be therein, in this specimen. In the soft parts on the outside of the bone we find an outer part, which is distinctly fibrous, — (treat- ment with strong acids indicate that the fibres are elastic enveloped in a gelatinous homogeneous substance) and an inner part (c) which abounds in (young) cells and which shows but faint fibrillation: (e) is a pink zone similar to (b) and adjoining an Haversian canal, in the lumen of which there appear also a group of cells similar to (o). The soft tissue surrounding the bone, blends with it, merges or passes into it, and we fail to see here such a schematic arrange- ment of cells (typical osteoblasts as they are described in the books) and which we are led to expect. The specimen was magnified about 500 diameters (Gundl. V. Eyep. Ill), and reduced in the drawing.

(2). Scraping the surface of such a bone, which has been kept in bichromate of potass solution after the periosteum is removed, we get these covering cells off the bone in a very natural condition, and Figure 6, Plate V, shows some of them. They are all nucleated, which can be demonstrated by the aid of acetic acid. The nucleus was not apparent on all when the drawing was made. Generally short processes are seen, and the drawings show the coarser ones. Finer processes would of course be very apt to be broken off.

(3). Figure 7, Plate V, is a section through part of the root of a calf's tooth showing the cementum and pericementum. We observe here, as in the kitten's femur, the calcified tissue with its lacunae and the processes from these and a very broad zone of uncalcified cementum with numerous lacunae, no canaliculi how- ever are apparent to the eye; just as in the layers b and e from the kitten's femur. As in the periosteum, we find an inner finely fibril la ted part of pericementum, rich in cells, and an outer with coarser fibres. The union of the enveloping parts to the tooth is also very intimate. (In parenthesis I may remark, that in speak-

52 a SIHLER.

ing of fibri Hated or fibrous tissue I am using only descriptive language; fibres and tubules are not so easily distinguished).

(4). Figure 8, Plate V, is a highly magnified drawing, a por- tion of a transverse section of a femur of a kitten some months old. The bones had been remaining in the staining fluid a long time, and thus one point of importance is brought out plainly. While in Figure 5, as well as in Figure 7, we see the pink zone quite homogeneous, we perceive here that darkly stained lines pass through it which we may be allowed to interpret as the future canal iculi.

(5). Treatment of such a section as shown in Figure 7 through the tooth, with strong muriatic acid brings out other important facts. The strong acid will here as elsewhere dissolve the homo- geneous gelatinous ground substance, it does this in the calcified part as well as in the pink zone, aud in so doing brings to light in the pink zone a network of fibres and tubules corresponding to the canalicular network of the calcified cementum. In fact after treatment with acid the calcified and uncalcified layers become one; the walls of the tubules, as in dentine, evidently correspond to a substance of the nature of elastic fibre.

The same observation can be made on the bone and periosteum. Acid shows that the pink zone is not homogeneous, although it appears so to the eye. In the bone and periosteum another fact is brought out by this reagent. After it has acted some time glistening fibres make their appearance in the periosteum and, by pressing on the ooverglass, one can make out that some of these periosteal fibres enter the bone.

Taking all these facts into consideration one may form the fol- lowing conception of the process taking place here on the outside of the bone, or wherever bone is formed, and on the root of the tooth. The cells in the deep layer of the periosteum, or of the pericementum, multiply and form blood vessels ; as they do so they remain in connection with their mother cells and in all probability form new connections with neighboring cells; these connecting processes afterwards become the canal iculi. In their vital processes these cells jointly excrete a gelatinous material and the elastic membranes, which partly if not altogether produce the striation observed in bone and so plainly visible in cementum ; the newest layer presents itself, when treated in the way indicated, as the pink zone; as the cells secrete layer upon layer they, as a

DENTINE AND OSSEOUS TISSUE. 53

whole, are carried outward further away 'from the finished bone- substance. Some of the cells however, get entangled— so to speak- in the secretion, and come to be, in the fully formed bone, the lacunae, (or at least their contents). At the same time as the layer of plastic cells moves outward, secreting the basis-substance, they spin out, or draw out their processes thus giving rise to the canal i- culi. Although these under ordinary circumstances are not easily recognized, they are already present from the beginning and are formed pari passu with the ground substance of the bone. All it needs to make them apparent is the infiltration of the newly formed tissue with lime salts.

One may compare the surface of a growing bone with that of a granulating ulcer; on the surface proliferation of new cells and formation of new blood vessels takes place (only in the bone they are a wide network while in an ulcer they form loops), and a little deeper in the deposition of new substance takes place ; in the one case the typical osseous tissue and in the other the cicatricial substance.

The view presented here on osteogenesis allows also enough liberty for the formation of the different varieties of bone, which vary, e. g., not unmarkedly in the young and the old, the character of the bone depending on the nature of the fibrillar or connective tissue forming it.

Kolliker and Virchow offer a different explanation of the form- ation of the canaliculi. Kolliker says, p. 222, 5th Ed., 1867, of his histology: "According to Virchow's discovery, which I can fully confirm, these cells [the periosteal cells] become stellate gradually, and are thus changed directly into the stellate bone corpus-

cles."

*

Virchow gives the following explicit account, p. 469, Cell. Path., 7th Am. Ed.: "The cartilage cells (and the same holds good of the marrow cells) during ossification throw out processes (become jagged) in the same way that connective tissue corpuscles, which we also originally found, do both physiologically and pathologically. These processes which in the case of the cartilage cells are generally formed after, but in that of the marrow cells frequently before, cal- cification has taken place, bore their way into the intercellular substance like the villi of the chorion do into the mucous mem- brane and into the vessels of the uterus, or like the Pachionian granulations (glands) through the calvarium."

64 C. SIHLER.

" The cells which thus result from the proliferation of the peri- osteal corpuscles are converted into bone corpuscles exactly in the way I described when speaking of the marrow. In the neigh- borhood of the surface of the bone the intercellular substance grows and becomes almost cartilaginous. The cells throw out processes, become stellate and at last the calcification of the intercellular substance ensues."

A view on the formation of osseous tissue differing from the one above worked out, is that of Waldeyer, which is gaining favor among histologists.

"The osteoblasts/' says Waldeyer, "are the embryonal cells forming the osseous tissue, a portion of the same (the nucleus dis- appearing) is changed into a gelatinous more or less fibrous texture, which during normal ossification takes up lime salts almost at the same time; of a certain proportion of these osteoblasts only the peripheral part of the protoplasm is thus changed, what is left remains behind as the nucleated bone corpuscle, imbedded in the intercellular substance, like a connective tissue corpuscle in the substance of tendon."

After describing the calcified cartilage and the changes it under- goes, Waldeyer gives a description of the parts in which the first deposition of bone takes place (the crypts of calcified cartilage with the medulla), which seems to m#e true and to fit into my theory fully as well or better than into his.

On p. 365 of the Archiv fur Mikroscopische Anatoraie, I, 1865, he makes a statement which I cannot bring in harmony with his Figure 2. He says: "At the time when the first bone substance is deposited upon the cartilaginous framework, there is not the trace of a separation to be observed between the osteoblasts and the medullary tissue. This occurs later, wheu a very distinct stratum of bone is deposited."

But on looking at the drawing we see a marked difference between the fibrous tissue in the centre of the cavity and the layer of "osteoblasts" lining the walls of calcified cartilage, no bone having as yet been laid down there.

Waldeyer continues his argument thus: "It is not difficult to ascertain here already the correctness of my view regarding the formation of osseous tissue, as I expressed it above. While the first bone substance is formed the medullary spaces are closely filled with osteoblasts, there is no room left for any excretion,

DENTINE AND OSSEOUS TISSUE. 55

excepting that at the same time a number of osteoblasts perish, which cannot be assumed, or a bone substance ought to be formed studded so thickly with lacunae as it is never found to be the case. This fact makes it to me very improbable that the ground substance of bone is a mass excreted by the osteoblasts."

The examination of these regions has never roused this difficulty in my mind, and if we again turn to the figures of Waldeyer himself, we find no lack of space, there is amply, room in the spaces produced by the openings of the cartilage cells for six times as many cells as are figured — hence also for a thin coating of bone.

Waldeyer continues : " One observes further that the peripheral parts of the single osteoblasts are changed, loosing their darkly granular appearance and applying themselves closely to the sinuous walls of the medullary spaces. Other osteoblasts in the neighbor- hood are in connection with these modified peripheral layers, they also with their metamorphosed outer layers approaching the former. The portion of protoplasm around the nucleus only remains un- changed. I take this change of the peripheral strata for the ex- pression of a metamorphosis into glue yielding substance, which at once takes up the lime salts/'

Looking at the figures, I fail to see any indications of such processes, especially can I not distinguish between unchanged osteoblasts and such as are dwindling, their bodies being changed into gelatinous substance. Heading this description one would also think that the deposition of new osseous substance was taking place all around the cells, around each individual cell, and that the substance was immediately calcified ; in fact one would expect a tissue somewhat like cartilage. But neither is the case, neither the laying down of bone substance around individual cells nor the immediate calcification. The new layer is in sections and always forms an uncalcified seam, in which here and there a "cell" is found.

Although there are disadvantages connected with the carmine method, as above described, yet there are some facts brought out by it very well; and the individual steps of the processes can I think be better followed than by the chromic acid method. Using chromic acid and decalcified tissue there are certain differences necessarily obliterated, which the other method brings out, and which are apt to make a strong impression. 6

56 C. SIHLER.

That the cells alter in character would be not easy to prove, as it depends on very slight changes in size, and the greater or less amount of granules, but if it should be the case, this fact would favor the theory supported in this paper very well indeed, as I shall show further on.

So does also the fact, that the cells in specimens which have been brushed, are partly free, partly adherent to the bone by their processes.

Waldeyer further points out, that the cells inclosed in the osseous substance are smaller than the osteoblasts, and says: "If we find however cells in formative action, it is difficult to conceive how they can effectually perform their functions, and at the same time undergo atrophy ."

This difficulty can easily be overcome by the examination of gland cells which have been resting, and such as have been made to secrete very actively; the former we find large, plump, with sharp outlines; the latter small, shrunken, shrivelled, their out- lines difficult to make out. We see here that cells which are secreting actively shrink very markedly; and might such a change not have been expected ?

I said above that it was not easy to distinguish with certainty minute differences in size. To support this statement, I would call attention to a figure, by Klein, in Sanderson's Handbook, a transverse section of a femur from a human foetus, treated with chromic acid ; I do not think that any one can perceive any differ- ence in size between the cells lining the medullary spaces and those inclosed in the lacunae.

To explain the process as taking place beneath the periosteum, Waldeyer adduces a cross-section of a foetal Tibia, (Plate XXII,* Figure 5) — at (a) we are to see osteoblasts. I have serious doubts, however, if at this place, and others, where Waldeyer thinks deposi- tion of new osseous tissue is taking place, the opposite is not occurring y namely, the absorption of the bone. There is a good deal of evi- dence that the latter is the case, — the jagged outline and character- istic excavations, — while there is no evidence at all that formation is just now taking place there. First there ought reasons to be given that formation is going on there at all before the specimen is used for demonstration. Treatment of the material with carmine

* Arch. f. Mik. Anat., 1865.

DENTINE AND OSSEOUS TISSUE. 5T

in the way described shows at once where excavation and absorp- tion is going on, where deposition of new bone is going on, and where the soft parts covering the osseous tissue are at rest.

The view here favored agrees with Kolliker's, excepting as regards the formation of the canaliculi, and probably' agrees with Gegenbaur's, (whose writings I have not had opportunity to ex- amine) if I may form a judgment from scattered references.

DESCRIPTION OF PLATE.

Fioubb 1. — Section through root of calf's incisor, a, pulp ; 6, uncal-

cified dentine; c, dentine ; d, cementum ; e, uncalcified cementnm ; /, pericementum.

Figure 2. — Section through pulp, odontoblasts and dentine; calf's

incisor, a, dentine ; b, uncalcified dentine ; c, odonto- blasts; d, pulp.

Figure 3. — Odontoblasts from calf's tooth.

Figure 4. — Pulp-cells from same.

Figure 5. — Section through femur and periosteum ; kitten at birth.

a, fully formed bone; b and e, uncalcified bone ; c, layer of cells forming bone ; d, outer periosteum.

Figure 6. — Osteoblasts ; cat's bone.

Figure 7. — Section through cementum and pericementum of calf's

tooth, a, cementum ; b, uncalcified cementum ; c, cementum forming cells ; d, outer part of cementum.

Figure 8. — 8ection through femur, kitten 3-4 months, deeply stained.

All drawings except Figure 1 were made under Gundlach V. Oc. 3, and reduced.

THE FIRST ZOEA OP PORCELLANA. By W. K.

BROOKS and E. B. WILSON. With Plates VI and VII.

Since 1835, when Thompson obtained the larva of a British species of Porcellana from the egg, this very remarkable zoea has frequently attracted the attention of natural ists, and we now have quite an extensive list of papers, giving a satisfactory account of the structure of the advanced zoea, and of its transformation into the adult crab. The bibliography of the subject is given, at length, in a recent paper by Faxon, (On some young stages in the devel- opment of Hippa, Porcellana and Pinnixa. Bulletin of the Museum of Comparative Zoology, at Harvard College, Vol. V, No. 11,) and it seems unnecessary to duplicate it here.

Most of the observers who have studied it started with the ad- vanced zoea which is frequently captured with the hand net at the surface of the ocean, and the few papers which notice the early stages of the larva were published so long ago, that a minute account of the young, as it leaves the egg, is still lacking.

During the latter part of June, 1880, we obtained, at the marine laboratory of the Johns Hopkins University, at Beaufort, N. C, a female specimen of Porcellana ocellata, Gibbes, with eggs, which we succeeded in keeping alive and in good condition until the eggs hatched, and we were thus supplied with an abundance of material for studying the early stages.

As all the members of the party were at the time fully occupied with other work, we undertook to study the larva together, and to make as many notes and drawings of the early stages as possible.

This paper is therefore the result of our combined observations, but the work of copying the original drawings, and of preparing the description has been done by W. K. Brooks. In the explana- tion of the figures the author of the drawing which was copied is named in each case, although in nearly every case, the accuracy of the observation was verified by an independent drawing by the other observer. 58

FIRST ZOEA OF PORCELLANA. 59

The larva immediately after its escape from the egg, is shown in Plate VI, Figure 1. It is able to rise from the bottom and to swim a little by flapping its abdomen, but until the next moult it spends most of its time lying nearly motionless upon the bottom.

The carapace makes a little more than two-fifths of the total length of the body, and is folded upon itself in such a way as to form a well defined transverse band running across its dorsal surface near the posterior edge. The posterior spines of the cara- pace do not seem to be at all invaginated, but they are very much convoluted and wrinkled, and their free extremities are bent forwards under the posterior edge of the carapace. Between the eyes the anterior end of the carapace forms a protuberant rounded front, and the convoluted and wrinkled rostrum is bent down towards the ventral surface. The eyes lie in deep notches on the anterior edge of the carapace, and they appear to be movable, although the stalks are very short.

The third pair of maxillipeds are small and rudimentary, while the first, Mpj and second, JHp', pairs are well developed, although their locomotor setse are not yet protruded, and the limbs are not moved but remain constantly in the position which is shown in the figure. The abdomen has five free movable somites, besides the sixth which is not separated from the telson, T.

The pigment is more conspicuous at this time than during the stages which follow, and consists of a number of pretty constant bright red spots. One of them is on the basal portion, and one on the flagellum of the second antenna, one on the mandible, M, one on the basal joint of the first maxilliped, two on the basal joint of the second and one on the third, as well as one about half way between the base and tip of the secoud; there is a rong dendritic spot on the posterior edge of the first, the second, the third, and the fourth abdominal somite, and a pair of spots on the telson.

The whole surface of the body is covered by a delicate embryo- nic cuticle, which is too transparent to be visible with the magni- fying power under which Figure 1 was drawn. This cuticle conforms to the outline of the body except on the two pairs of antenna? and the telson. It will be described, in detail, later, in the account of the appendages.

Some of the larvae free themselves from it within a couple of hoars, and assume the form shown in Plate VI, Figure 5, while others do not escape from it until nearly or quite twenty-four hours

60 W. K. BROOKS AND E. B. WILSON.

after they leave the egg. After this first moult the stalks of the eyes, (see Figure 6), elongate, the fold at the posterior edge of the carapace is stretched out so that the latter is now about half as long as the whole body ; the rounded front disappears, and the con- volutions and wrinkles of the rostrum and spine are no longer seen, although these processes are still rolled up, as shown in the figure. Figure 5 shows them as they appeared in the zoea which was drawn, but the form of the bends is not at all constant.

The swimming hairs on the first and second maxillipeds, Mp> Mp'} are extended, and these appendages, as well as the telson, are now used as locomotor organs. Spines have now made their appearance upon the posterior edges of the third, fourth and fifth abdominal somites, and the rostrum and processes of the carapace are covered with short hairs.

In from one to two days after hatching the rostrum and pro- cesses become extended, as in Plate VII, Figure 8, and the zoea assumes the familiar form which has been described and figured by many observers.

The Appendages:

The first antenna of the newly hatched larva is shown in Plate VI, Figure 2, and that of the fully developed zoea in Plate VII, Figure 3.

In the first stage it is covered by the delicate embryonic skin, which follows the outline of the appendage very closely, except at the tip where it is produced into two long, broad, flattened, pointed setse," which are fringed with smaller hairs. These structures, which seems to be swimming hairs, are not present in the zoea after the moult, but ki the first stage the antenna carries a single stout sensory hair which, as shown in Plate VI, Figure 2, extends into one of the swimming hairs, more than halfway to the tip. After the moult, Plate VII, Figure 3, the appendage ends in a number of long blunt sensory hairs, from the bases of which fine fibres run downwards to a large club-shaped granular mass, which appears to be ganglionic in nature.

The second antenna is shown before the moult, in Plate VII, Figure 1, and after the moult in Plate VII, Figure 2. It is essen- tially alike in both stages, but before the moult is loosely invested by the embryonic skin, which is loose and much larger than the true appendage. It consists of a swollen basal portion d, which carries a short pointed external branch, and a longer internal branch.

FIB ST ZOEA OF PORCELLANA. 61

The mandibles and maxillae are shown before the moult in Plate VII, Figure 7, and after the moult, in Plate VI, Figures 3, 4, and Plate VII, Figure 5.

In the first stage, Figure 7, Plate VII, these three appendages are folded together, and covered by the embryonic skin which is nearly conformable to their surface, although, as shown by the light outer line in the fieure, it does not follow all the folds. No trace of a palpus could be discovered on the mandible, and the hairs at the tip of the maxillse were almost completely invaginated into the appendages.

After the moult these three pairs of appendages become func- tional, and have nearly the adult character. The mandibles, Plate VII, Figure 5, and Plate VI, Figure 6, M> are not exactly alike, but exhibit that slight departure from bilateral symmetry so frequently found in these appendages. No trace of a mandibular palpus could be found, although there was a small area where the integument had been broken in each of the two specimens which were dissected ; and as this area, shown in the figure, was at the same place in both cases, the fracture may have been produced by the removal of a palpus.

The first maxilla, Plate VI, Figure 3, and Figure 6, Mx9 consists of a two-jointed basal portion, a, 6, with stout cutting hairs, and a slender endopodite c, which in one specimen ended in two, and in another specimen in three long, slender, irregularly plumose hairs. The distal joint, 6, of the basal portion carries upon its cutting edge, one row of five stout spines and a second row of four slender 8 pines parallel to the larger ones. In the specimen figured, the proximal joint, a, was twisted so that its inner surface was shown, and the posterior edge is therefore the one at the left of the figure. It carries five long, stout, plumose spines, and at the posterior angle of its cutting edge a single spine without secondary hairs. No trace of an exopodite or scaphognathite could be detected in this appendage.

The second maxilla, Plate VI, Figure 4 and Figure 6, Mx\ con- sists of a three-jointed basal portion with short stout hairs; a two- jointed endopodite, 4, with longer hairs ; and a long flat exopodite,

c, with five long hairs at its distal, and a long plumose flagellum,

d, at its proximal end.

In the first stage, the first and second maxillipeds, Plate VI, Figure 1, Mp9 Mp'y are fully developed, although the presence of

62 W. E. BROOKS AND E. B. WILSON.

the embryonic skin prevents the extension of the locomotor hairs.

In Figure 1, the rudimentary third maxilliped is shown behind the base of the second.

In Plate VII, Figure 4, the third maxilliped, c, is shown, more highly magnified, lying in the same series with the bases, a and 6, of the first and second. A fourth appendage, no doubt the first pereiopod, is also represented at this stage by a bud or rudiment, rf, and the appendages, 6, o, and d, are furnished with little buds, which would seem to be rudimentary gills. After the moult we were not able to detect either the appendage, d, or the gill-like processes.

After the embryonic skin is moulted, the locomotor hairs of the first and second maxillipeds lengthen and these appendages become functional, while the third pair remain rudimentary. Figure 6, Plate VII, shows the first and second maxillipeds soon after the moult, and hardly calls for explanation.

The embryonic skin conforms closely to the surface of the ab- domen and telson, although it appears to have no trace of a division into somites.

Figure 7 of Plate VI shows one-half of the telson of Figure 1 before the embryonic skin is shed. A comparison with Figure 6, T9 will show that the great difference which has been pointed out by Faxon and others between the telson of the embryonic skin and that of the zoea in the ordinary crab, does not occur in Porcellana, but that the two are here nearly alike.

The five pairs of long swimming hairs of the zoea are, before the moult, about half invaginated, and the extended portion, Plate VI, Figure 8, is finely plumose. The hairs of the embryonic cuticle are much stouter, and their edges are not plumose, but they agree with those of the zoea, in number and arrangement.

The outer hair, or marginal spine of the telson, has the same appearance before the moult that it has afterwards.

EXPLANATION OF THE FIGURES.

PLATE VI.

Figure 1. — Zoea immediately after its escape from the egg, seen from

the left Bide. From a drawing by W. K. Brooks.

FIRST ZOEA OF PORCELLANA. 63

Figure 1. — Continued.

At first antenna; An, second antenna; Mf mandible; Mp, first maxilliped; Mp', second maxilliped; R, rostrum ; T, telson.

Figure 2. — First antenna of the same larva, more highly magnified.

From a drawing by W. K. Brooks.

Figure 3. — First maxilla of the larva shown in Figure 5. From a

drawing by W. K. Brooks.

a, proximal joint of basal portion; b, distal joint of basal portion; c, endopodite.

Figure 4. — Second maxilla of the larva shown in Figure 5. From a

drawing by W. K. Brooks.

a, three-jointed basal portion; 6, two-jointed endo- podite; c, scaphognathite ; d, flagellum.

Figure 5. — Zoea, seen from the right side, immediately after moulting

the embryonic skin. From a drawing by E. B. Wilson. A, first antenna; An, second antenna; Mp} first max- illiped; Mp' , second maxilliped; R, rostrum.

Figure 6. — Ventral view of the same zoea, one day after moulting the

embryonic skin. From a drawing by E. B. Wilson. A, first antenna; An, second antenna; L, labrum, M, mandible; Mp, first maxilliped; Mp' , second maxilli- ped; Mx, first maxilla; Mx\ second maxilla; R, ros- trum ; T, telson.

Figure 7. — Dorsal view of right half of telson of the larva shown in

Figure 1. From a drawing by E. B. Wilson.

Figure 8. — One of the setae of Figure 7, more highly magnified.

From a drawing by E. B. Wilson.

PLATE VII.

Figure 1. — Second antenna of the larva shown in Plate VI, Figure 1.

From a drawing by W. K. Brooks, a, embryonic skin ; 6, external branch ; c, internal branch ; d, enlarged basal joint.

Figure 2. — Second antenna of the zoea shown in Plate VI, Figure 5.

From a drawing by W. K. Brooks. Letters of refer- ence as in Figure 1.

Figure 3. — First antenna of the zoea shown in Plate VI, Figure 5.

From a drawing by W. K. Brooks.

7

64 W. K. BROOKS AND E. B. WILSON.

Figure 4. — Basal joints of the maxillipeds of the lar?a shown in Plate

VI, Figure I. From a drawing by W. Brooks. a, base of first maxilliped ; 6, base of second maxilli- ped; c, third maxilliped; d, first pereiopod; e, edge of carapace.

Figure 5. — Mandible of the zoea shown in Plate VI, Figure 5. From

a drawing by E. B. Wilson.

Figure 6. — First and second maxillipeds of the zoea shown in Plate

VI, Figure 5. From a drawing by W. K. Brooks.

Figure 7. — Mandible and maxilla of the larva shown in Plate VI,

Figure 1. From a drawing by W. K. Brooks. M, mandible; Mx, first maxilla ; Mx', second maxilla.

Figure 8. — Side view of the zoea, one day after moulting the embryo- nic skin. From a drawing by £. B. Wilson.

ERRATA.

Page 60. bottom line, fir "external," read "internal." for " internal," read " external."

THE STUDY OP HUMAN ANATOMY, HISTORI- CALLY AND LEGALLY CONSIDERED.1 By

EDWARD MUS8EY HARTWELL, M. A., Fellow of the Johns Hopkins University.

Part First.

" Practised architects, before they venture in thought to build a new edifice, to strengthen an old one, or restore a ruined one, first consider carefully and examine closely all the minute parts of such structures. So, physicians, indeed, before they endeavor to care for the human body and preserve it from the diseases which threaten it, ought to know very accurately, and to a nicety, all the parts of that body. Anatomy, the eye of medicine, furnishes such knowledge. Verily, the beginnings, the foundations, and the sources of origin of the medical art are, without the light and vision of anatomy, shrouded in thick darkness; wherefore, it is not inaptly called by Johannes Montanus, the alphabet of medi- cine." So wrote Rolfincius, in his " Dissertationes Anatomic©," published at Nuremberg, in 1656.

When we of to-day seek the origin of this "alphabet of medi- cine," we turn to the East, whence we are accustomed to derive the beginnings of all our arts; but we find the history of ancient anatomy to be almost a blank page. Priest, and law-giver, and people were all averse to anything like the dissection of the human body. The Egyptians, Hebrews, Greeks, Romans, and Arabs, alike regarded with abhorrence the mutilation of the dead. There is abundant proof of this in their laws and customs touching burial and defilement.

It is said that Democritus, of Abdera (460 B. C), the friend of Hippocrates, was the first to dissect the human body. However

1 Portions of the following paper have been printed already in the Journal of the American Social Science Association; the Boston Medical and Surgical Journal and the Brooklyn Annals of Anatomy and Surgery. In its present form it contains much new material ; and embodies the result of the latest •statistics and most recent legislation so far as I could ascertain.

65

66 E. M. HABTWELL.

that may be, it is as the Laughing Philosopher, and not as the Father of Anatomy, that be has influenced mankind. It was in what we fondly call " Egyptian darkness," and through the favor of an enlightened despot, that the first school of anatomy was founded at Alexandria, three hundred years before Christ, by Ptolemy Soter. "Braving," says Bouchut, "all prejudices, and considering that the interests of science ought always to outweigh those of the individual, Ptolemy authorized the dissection of human dead bodies, and himself set the example by beginning to dissect with the physicians gathered around him." Herophilus, and Erasistratus, his pupil, made the school of Alexandria famous and influential ; their contributions to anatomy were genuine and considerable. No name worthy of mention, beside theirs, is to be found in the history of anatomy, until we come to that of Mondino, Professor at Bologna, who first publicly dissected in Europe, early in the fourteenth century. Yet, in the interval between the deca- dence of the Alexandrian school, which followed hard upon the death of its founders, and the rise of the Italian schools of anatomy, Aristotle, Galen, Celsus, and the Arabists, lived and wrote. George Henry Lewes declares that "Aristotle has given no single anatomical description of the least value." Daremberg, Galen's editor and translator, who says he has repeated every one of Galeu's dissections, is convinced that he used only the lower animals. Celsus expressed himself as a believer in the utility of human dissection. The medicine and surgery taught by the Arabs, at least so far as its anatomy was concerned, was borrowed « from the Greeks.

Previously to the rise of human anatomy in Italy; Galenism, founded on the dissection of the lower animals, notably the ape, dominated the known medical world. Galen had written his "De Usu Partium Aniraalium," as a prose hymn to the Deity. The hierarchy commended his system which was upheld as scientific orthodoxy, alike by political and religious authority; all research capable of contradicting his views was condemned. The first Italian anatomists were quite content to expound Galen. One of the Arabists, Abdollaliph, criticised the slavish dependence of his contemporaries on books. He commended those who, like him- self, repaired to burial grounds to study the bones of the dead; but he seems never to have dreamed that anything could be learned from a like scrutiny of the soft parts.

THE STUDY OF HUMAN ANATOMY. 67

Galenism died hard, even in Italy where it was first attacked. How tenacious it was of life is well shown by Malpighi, who was born in 1628, the year that Harvey first published his "Essay on the Motion of the Heart and Blood." Harvey never saw the passage of the blood through the capillaries; Malpighi discovered those vessels and first demonstrated the flow of blood from the arteries into the veins. Malpighi writes: "In the meantime, con- tentions being raised among studious men, especially the younger, both practical and theoretical, and the new doctrines growing daily into more credit, the senior professors of Bologna were inflamed to snch a pitch, that, in order to root out heretical innovations in philosophy and physic, they endeavored to pass a law whereby every graduate should be obliged to take the following additional clause to his solemn oath on taking his degree, viz: 'You shall likewise swear that you will preserve and defend the doctrine taught in the University of Bologna, namely, that of Hippocrates, Aristotle, and Galen, which has now been approved of for so many ages; and that you will not permit their principles and conclusions to be overturned by any person, as far as in you lies.'" "But/' says Malpighi, "this was dropped and the liberty of philosophizing remains to this day."

Practical anatomy was taught at Padua it is said, as early as 1151 ; Haeser, in the third edition of his Geschicte der Medecin says that: " in the year 1238, Kaiser Frederick II. ordered, at the suggestion of Marcianus, chief physician of Sicily, that every five years a corpse should be dissected publicly, and that physicians and surgeons should be admitted, according to their rank, to the dissection." It is elsewhere stated that Frederick forbade, in the code for Sicily, any one to practice surgery unless he had been in- structed in anatomy. There is no dispute, however, that Mondino publicly dissected two subjects as early as 1315; and. some writers give 1308 as the date.

We find many bulls of Popes and canons of Councils regarding the study and practice of physic and surgery by monks; from the time of the Council of Laodicea, in 366 A. D., when the priest- hood were forbidden to study enchantment, mathematics, and astrology, and the binding of the soul by amulets, till 1215, when Pope Innocent III. is said to have fulminated an anathema against bloody operations in surgery. Although these utterances of the Church are interesting, we pass them by as being outside the scope of this paper.

68 & M. HARTWELL.

The edict of Boniface VIII., however, published in 1300, affected the progress of practical anatomy, and is worthy of note. In 1299, Pope Boniface VIII. forbade, under pain of excommuni- cation, any one to boil, cut up, or dry the bodies of the dead. Such an act he characterized as barbarous and abhorrent to Christian piety. Raynaldus, in whose " Annates Ecclesiastici, Lucae, 1749," the edict of Boniface is found, says that such cus- toms "had prevailed in regard to those who, having undertaken a pilgrimage to the East, died in foreign parts; and in order that their bones might be freed from flesh, and so easily carried about without the fear of corruption. And yet we know," he adds, " that the body of Saint Luke was boiled by his friend8.,, It is hardly probable that Pope Boniface directed this edict primarily against anatomy. Edward I., of England, directed that the flesh should be boiled from his bones and that they should be carried to battle in a bag by his successor, in order to terrify his enemies. The story of Douglas and the heart of Robert Bruce is familiar to all. It is quite likely that Boniface launched his anathema iu order to restrain such practices as these; nevertheless, his edict proved an obstacle to anatomical studies. Mondino apologizes for not making the most exact study of the bones of the skull, saying : " the bones beneath the basilar bone are not to be clearly distinguished, unless they be boiled'; a sin which I have .been accustomed to shun." Hyrtl, the famous German anatomist, holds that the edict of Boniface was in force till 1556, when the Emperor Charles the Fifth, the patron of Vesalius, ordered the question to be put to the theologians of the University of Sala- manca, " Whether or not it could be allowed, without violating one's conscience and incurring the suspicion of criminality, to cut up human dead bodies ? " " Et respondisse Universtiatem, Licere" says Rolfincius, quoting a still earlier writer.

That dissection was not universally banned by the Church before the Divines of Salamanca pronounced it lawful, may be seen from the action of Pope Sixtus IV., in 1 482. In that year, in a letter addressed to the rector, doctors, and students of the University of Tubingen, Sixtus granted a special and full dispensation to those who should receive the cadavera of certain malefactors executed for capital crimes in accordance with the civil law: u per justitiam secularem" is the phrase in the original. They were given per- mission to dissect and dismember these dead bodies, inasmuch as

THE STUDY OF HUMAN ANATOMY. 69

they desired thereby to render themselves learned and skilful in the art of medicine, provided they would bury in the customary manner such condemned men after they should be dissected and dismembered.

The Grand Council of Venice, in 13Qg, passed a decree ordering the medical college of that city to undertake a dissection once a year. It is claimed that in Prague, as early as the foundation of the University in 1348, the executioners were enjoined to deliver the cadavera of malefactors to the school of medicine. Duke Albrecht IV. imported an Italian anatomist, named Galeazzo, to introduce the art of dissection into Vienna ; where the first anatom- , ical demonstrations before the medical faculty were made in 1404.

In France, as early as 1376, Louis of Anjou permitted the sur- geons of Montpellier to take the body of an executed criminal annually for dissection. Charles the Bad. King of Navarre and Lord of Montpellier, ratified this grant in 1377; as did King Charles VI. in 1396 ; and King Charles VIII. in 1484, and again in 1496. A similar grant was made in Scotland in 1505, as we learn from the following extract taken from the Charter given by the Town Council of Edinburgh to the Surgeons' Company, July 1, 1505, and ratified by King James IV. in the following year: " And als that everie man that is to be maid frieman and maister amangis ws be examit and p^evit in thir poyntis following Thatt 18 to say That he knaw anatomea nature and complexioun of every member In manis bodie. And in lyke wayes he knaw all the vaynis of the samyn thatt he may mak flewbothomea in dew tyme. And als thatt he knaw in quhilk member the signe hes domination for the tyme for every man aucht to knaw the nature and substance of every thing thatt he wirkis or ellis he is negligent. And that we may have anis in the yeir ane condampnit man after he bedeid to mak anatomea of quhairthrow we may haf experience Ilk ane to instruct others And we sail do suffrage for the soule." By Act of Parliament, 32 Henry VIII., cap. 42, in 1540, it was granted to the Barber-Surgeons of London to take " yearly forever

four persons condemned, adjudged and put to Death for

Felony by the due Order of the King's Highness, and to

make Incision of the same dead Bodies, or otherwise to order the aarae after their said Discretions at their pleasures, for their further and better Knowledge, Instruction, Insight, Learning, and Expe- rience in the said Science or Faculty of Surgery."

70 E. M. HABTWELL.

Vesalius, a Fleming, born in 1514, did more than all bis prede- cessors to overthrow Galenism and place medicine upon a rational basis, and well deserves his title of the Father of Modern Anatomv. Yet, despite the concessions we have noticed made by prelates, kings and parliaments to, the early anatomists, Vesalius and his students were obliged, in the words of Hallam, " to prowl by night in charnel-houses, to dig up the dead from the grave ; they climbed the gibbet in fear and silence to steal the mouldering carcass of the murderer at the risk of ignominious punishment and the secret stings of superstitious remorse." Vesalius began to dissect while a youth in his teens. For a time he studied under the famous French anatomist, Jacques Du Bois, who demonstrated the anatomy of Galen on the carcasses of dogs. But Vesalius forsook Paris for Italy, drawn thither by the reputation of the schools whence Leonardo da Vinci and Michael Angelo derived their knowledge of human anatomy. Before he was twenty -eight, as has been well said, " Vesalius discovered. a new world," and held at one time the professorship of anatomy in the universities of Pisa, Padua and Bologna. He died the victim of the Spanish Inquisition. His inspection, with the consent of the relatives, of the body of a Spanish grandee, whose heart feebly contracted under the knife, brought him before the Inquisition, and would have led him to the stake but for the intercession of the King. Compelled to journey to Jerusalem by way of penance, Vesalius was shipwrecked, in 1564, on the island of Zante. It is said that' he there starved to death, and that unless a liberal goldsmith had defrayed the funeral charges, the remains of the greatest anatomist the world had seen would have been devoured by birds of prey.

The Italian schools under Vesalius and his successors, Fa 1 lop i us, Columbus and Fabricius, exerted a wide and potent influence upon European medicine. This influence was sooner felt and more marked in France, Germany and Holland than in Eng- land and Scotland. The following statements, made by Billroth, may serve to indicate the favor in which anatomy was held in Germany :

In the Privilegia granted by the Landgrave Wilhelm von Hessen to the University of Marburg, in 1653, it is provided that " in the medical faculty at the start there shall be two doctors in pay, who, in addition to the theory, shall conduct the practice of anatomy and of botany with the youth." The statutes of the

THE STUDY OF HUMAN ANATOMY. 71

medical faculty at Marburg for the same year, Title IV, read as follows : —

"(1.) It is clear that anatomy, next after psychology, forms the chief part of universal physiology. Since there is a twofold method of teaching it, one that is ordinarily practiced in anatomical theatres in the presence of many spectators, and the other which is employed by the holders of scholastic chairs, let neither of them be intermitted. Let both of them, as well publicly as privately, be practiced.

"(2.) Let also' the art of dissection and of skillfully handling and applying the knife in individual parts be shown, in order that a difference may be noted between physical and medical or practical anatomy. The various skeletons, also, both male and female, of common and exotic animals shall be prepared, in order that not only the structure of the skeleton, but also the whole of oste- ology, may become known to students of medicine as well as of surgery.

"(3.) Let pregnant women be dissected as well as others. Let mid-wives as well as others be admitted.

"(4.) Let not those who are condemned to death be opened alive, but let living things of every kind, as insects, serpents, aquatic animals, birds, and quadrupeds, be dissected. Especially let those studying anatomy observe, more precisely than butchers would, domestic quadrupeds while they are being slaughtered.

"(5.) Moreover, let the bodies of atrocious criminals, whether they have been beheaded or hanged, be designated for dissection. Let them not be kept back by the magistracy when they are sought for this purpose, in order that those who have done as much evil as they could when alive, may, after death, on the other hand, be of as much service and use as possible/'

We shall confine our attention chiefly to the history of anatomy in Great Britain; inasmuch as in the development of anatomy in America, the influence of Edinburgh and London is more readily traced than that of Paris and Leyden.

Twenty-five years after the passage of the Act of 32 Henry VIII., Queen Elizabeth granted to the College of Physicians, of London, the bodies of four felons executed in Middlesex, " that the president or other persons appointed by the college might, observ- ing all decent respect for human flesh, dissect the same." In 1663, Charles II. increased the number of felons' bodies, annually 8

72 E. M. HABTWELL.

granted to the physicians, to six. The Act of 22 George II., c. 37, 1752, required the dissection or hanging in chains of the bodies of all executed murderers in order that " some further Terror and peculiar Mark of Infamy might be added to the Punishment of Death." The provision of this Act regarding the dissection of murderers remained unrepealed till the passage of the so-called Warburton Anatomy Act, in 1832, while the provision regarding the hanging of a murderer's body in chains remained in force till 1861, when it was repealed.

These were the only legalized sources for the supply of anatomi- cal material in England prior to 1832. Such provisions might, at first sight, seem generous and ample, yet they were not. We find Dr. William Hunter, in 1763, in vain asking of the King a grant of land sufficient for the site of an anatomical school in London, which he proposed to endow with something like £7,000, and one of the finest anatomical collections in Europe. In his memorial to the Earl of Bute, Hunter writes: "Of the very few who profess or teach this art iu any part of Great Britain, London excepted, there are none who can be supplied with dead bodies for the private use of students. They can with difficulty procure only so many as are absolutely necessary for the public demonstrations of the principal and well-known parts of the body. Hence it is that the students never learn the practical part, and the teachers them- selves can hardly make improvements, because they cannot have subjects for private experiments and enquiries. Anatomy was not upon a much better footing, even in London, till the year 1746."

In 1832, Parliament passed the Warburton Anatomy Act, which is still in force throughout Great Britain and Ireland — in all its essential features. To understand its significance and that of "Burking," which really caused Parliament to enact it; we must glance at the Edinburgh School of Anatomy.

We have already noticed the grant of anatomical material con- tained in the charter of the Surgeons' Company, made in 1505. The beginning of the Edinburgh Anatomical School was in 1694; when the Town Council, on the 24th of October, in response to the petition of Alexander Monteith, granted him "any vacant, waste room in the correction house, or any other thereabouts belonging to the Town." Monteith also obtained a grant of "those that dye in the correction house; and the bodies of fund- lings that dye upon the breast." The Surgeons' Company were

THE STUDY OF HUMAN ANATOMY. 73

granted, nine days later, "the bodies of fondlings who dye betwix the tyme that they are weaned and their being put to schools or trades; also the dead bodies of such as are stiflet in the birth, which are exposed and have none to owne them; as also the dead bodies of such as are/elo de se and have none to owne them; like- waves the bodies of such as are put to death by sentence of the magistrat, and have none to owne them." Certain interesting conditions were attached to the grants to Monteith and the Sur- geons. The dissection was to be during the winter, from one equinox to the other; all the "gross intestines" were to be buried within forty-eight hours, and the rest of the body within ten days at the grantees' expense. The regular apprentices of the Surgeons were to be admitted at half price, and any magistrate who thought fit might attend the dissection. In the grant to the Surgeons, no mention is made of the gross intestines, according to Dr. J. Struthers, from whose sketch of the Edinburgh Anatomical School these facts are taken ; but it is provided " that the petitioners shall, before the terme of Michaelmas 1697 years, build, repair, and have in readiness, ane anatomicall theatre where they shall once a year have ane public anatomicall dissection, as much as can be showen upon ane body, and if the failzie thir presents to be void and null." The Anatomical Theatre of the Surgeons was reported finished to the Town Council, December 17, 1697. The Council ratified its grant of 1694, and, the same day, the Surgeons chose a committee "to appoint the method of public dissections, and the operators." In 1705, the Council gave <£15 salary to Robert Elliott, the first Professor of Anatomy in Edinburgh. In 1720, the Town Council elected Alexander Monro, primus, Professor of Anatomy. In 1725, he removed from Surgeons' Hall to the University buildings, because of the violence of a mob which had attempted to demolish the Surgeons' Theatre, on account of the supposed violation of graves. In 1722, the apprentices of the Surgeons' Company were obliged, in their indentures, to subscribe to "an obligation that they would altogether avoid raising the dead."

Under the Monros, father, son and grandson, who held between them the University Chair of Anatomy from 1720 till 1846, the school became widely famous. Many of the early American phy- sicians and anatomists studied at Edinburgh; where, early in this century, there were several extramural private schools of anatomy.

74 E. M. HARTWELL.

Of these, ' that of Dr. Robert Knox was the most famous and frequented. In the winter of 1828-29, he bad a class of 505: the largest in Europe.

For years the demand for anatomical material had exceeded the legal supply in Great Britain. As early as 1826, Parliament was petitioned, but in vain, to give aid and protection to the anato- mists,— who were forced to depend on the resurrection men for subjects. Bodies often brought £10 each, in Edinburgh and London; in one instance a subject was sold for £30. When the home supply ran short, the Scotch anatomists were furnished with stolen bodies from England, Ireland, and even France. "The increased demand and higher pay for material/' says Lonsdale, (Knox's biographer), "generated sad recklessness and brutality. Quarrels arose over the spoils; the jealousy of rival factions of the different schools, and the frequent attempts to outwit each other, led to personal denunciations and a fearful publicity." In response to numerous petitions from the medical profession, a "Select Com- mittee of the Commons/' to inquire into the hindrances to the study of anatomy, was appointed April 22, 1828. Its report was rendered on the twenty-second of July, following. In 1788, the Court of King's Bench decided, in the first reported case of the sort, that it was a misdemeanor at common law to carry away a dead body from a church-yard, although for the purpose of dissec- tion, as being an offence contra bonos mores and common decency. The Select Committee stated in its report, which was favorable to the petitioners, that, under the law as then interpreted, there was scarcely a student or teacher of anatomy in England who was not indictable for a misdemeanor ; and also that medical men " were liable in a civil action to damages for errors in practice, due to professional ignorance; though at the same time they might be visited with penalties as criminals for endeavoring to take the only means of obtaining professional knowledge." It was not until the following year, when the complaints of the anatomists and the report of the committee had been emphatically endorsed by the "Burking" horrors of Edinburgh, that leave was obtained, on the fourth of May, to bring in a " Bill, to Prevent the Disinterment of Dead Bodies, and for the Better Regulation of Our Schools of Anatomy."

On the second of November, 1828, it was noised about in Edin- burgh that a woman had been murdered on All Hallow Eve for

THE STUDY OF HUMAN ANATOMY. 75

the sake of her body, which was found in the dissecting room of Dr. Knox. In the investigation which followed it was discovered that William Hare, the keeper of a low lodging house in the West Port, and one of his lodgers, William Burke, had, within less than a year, committed sixteen murders, and disposed of the bodies of their victims to the teachers of anatomy. The " Burke" method was to suffocate the victim, already dead drunk. Throttling was not resorted to: the nose and mouth were kept tightly closed, and the smothering was soon effected. It was impossible to connect Knox with these villians in any way, except as a receiver of stolen goods for the benefit of the public. Hare turned State's evidence, but Burke was found guilty, hanged and dissected. His skeleton adorns the Anatomical Museum of the University of Edinburgh.

The Bill alluded to above was brought into Parliament May 5, 1829, but was thrown out in the House of Lords a month later. It was not until August 1, 1832, after a long discussion in which Sir James Mackintosh and Mr. Macau lay took part, that the " Warburton Bill for Regulating Schools of Anatomy " was enacted. At this distance in space and time the deliberateness of Parliament seems a trifle strained in the face of such facts as we have stated ; but one of the chief glories of the British Constitution is its slow growth, we believe.

The Warburton Act is, with some trifling amendments, still in force. Its effect has been to protect the sepulchres of the dead and, in the long run, to furnish an adequate supply of subjects. As, however, Massachusetts anticipated Great Britain by more than a year in legalizing anatomy, in a law based upon the same principles as those embodied in the English Act, we forego any special consideration of the terms and provisions of the latter.

Part Second.

ANATOMY IN AMERICA.

European and American anatomy have both developed along the same lines, but the European type is more highly specialized. Nearly all the developmental stages through which European anatomical science has passed are to-day represented in various States of the American Union. In some States it is a secret and perilous pursuit; in others it has gained legal protection ; in a few it has attained, perhaps, to the dignity of an ungenerously fostered science.

76 E. M. HARTWELL.

The earliest utterance in America, in recognition of the import- ance of anatomical studies, seems to have been made in Massachu- setts. In " The Cleare Sun-Shine of the Gospel Breaking upon the Indians in New England " is found a letter dated " Roxbury, 24 September 1647," from John Eliot to the Rev. Thomas Shep- hard of " Cambridge in New England." The Apostle declares of the Indians that "all the refuge they have and relie upon in time of sickness is their Powwaws, who, by an tick, foolish and notional conceits delude the poor people, so that it is a very needfull thing to informe them in the use of Physick, and a most effectual 1 meanes to take them off from their Powwawing. Some of the wiser sort I have stirred up to get this skill ; I have showed them the Anat- omy of man's body, and some generall principles of Physick. I have had many thoughts in my heart that it were a singular good work, if the Lord would stirre up the hearts of some or other of his people in England to give some maintenance toward some Schoole or Collegiate exercise this way, wherein there should be Anatomies and other instructions that way." It is unlikely that the Apostle Eliot added dissections to his lectures on "the Anat- omy of man's body ; " for later in the same letter he deplores the fact that " our young students in Physick have onely theoretical 1 knowledge, and are forced to fall to practice before ever they saw an Anatomy made," and says, " We never had but one Anatomy in the Countrey, which Mr. Giles Firman (now in England) did make and read upon very well."

The "first Anatomy in the Countrey" was doubtless made without the warrant of legal enactment; certainly the majority of dissections since then have been so made. The first statutory provision regarding anatomy in America seems to be the Massa- chusetts Act of 1784, by the terms of which the bodies of those killed in duels and of those executed for killing another in a duel might be given up to the surgeons "to be dissected and anato- mized." In 1831 Massachusetts anticipated all her sister States, and England as well, by legalizing the study of "anatomy in certain cases."

In the Diary of Samuel Sewall, of Boston, recently published by the Massachusetts Historical Society, is found under date of September 22, 1676, the following entry : " Spent the day from 9 in the M. with Mr. [Dr.] Brakenbury, Mr. Thomson, Butler, Hooper, Cragg, Pemberton, dissecting the middle-most of the

THE STUDY OF HUMAN ANATOMY. 77

Indians executed the day before. X, who taking the fp in hand, affirmed it to be the stomach."

The earliest reference that I have found to a post-mortem ex- amination in America is contained in a manuscript order of the Council of Lord Baltimore, dated St. Mary's, in Maryland, July 20, 1670. In it John Stansley and John Peerce, Chyrurgeons, are ordered to view, on Monday, August 8, 1670, the head of one Benjamin Price, supposed to have been killed by the Indians. It was brought out in connection with the Salem witchcraft trials, in 1092, that "about seventeen years before," a jury had been impan- elled upon the body of a man that had died suddenly in the house of Giles Corey, and that the jury, among whom was Dr. Zerub- babel Endicott, found the man " bruised to death, and having dodders of blood about the Heart/' This would indicate that a post-mortem examination was made in Massachusetts as early as 1675, fifteen years prior to that made on the body of Governor Slaughter, of New York, which is usually cited as the first recorded autopsy in America. In 1690, Governor Slaughter died suddenly, under circumstances which excited suspicions of poisoning. Dr. Johannes Kerf by le, assisted by five physicians, examined the body. The Council ordered £8 8 s. to be paid the surgeons for their ex- amination.

It is recorded that Dr. John Bard and Dr. Peter Middleton, of New York city, in 1750 injected and dissected the body of Her- manus Carroll, an executed criminal, " for the instruction of the young men then engaged in the study of medicine." This was thirty-nine years before the State of New York legalized the dis- section of the bodies of malefactors executed for arson, burglary, or murder. Though Pennsylvania passed no anatomy Act until 1867, the first American medical school was organized in Phila- delphia in 1765, by Drs. Morgan and Shippen, natives of that city. Dr. William Shippen, Jr., a pupil of John and William Hunter, gave, in 1762, a systematic course of lectures on anatomy. This first course of lectures by Dr. Shippen, is usually termed the first full and scientific course of anatomical lectures given in America ; although Dr. Cadwallader, as early as 1751, made dissections for the benefit of the physicians of Philadelphia, and Thomas Wood, surgeon, in 1752 advertised in the New York papers "a course on osteology and myology in the city of New Brunswick, N. J.," to be followed, in case of proper encouragement, by a course in angi-

78 E. M. HARTWELL.

ology and neurology, and a course of operations on the dead body. It should also be noted that Dr. William Hunter, educated at Edinburgh under the elder Monro, who came to America in 1752, gave lectures on anatomy and surgery in Newport, R. I., in the years 1754, 1755, and 1756.

Shippen's courses were so successful that in 1765 the Medical College of Philadelphia was organized with two professorships. Dr. Shippen held the chair of " anatomy and surgery ; " that of the "theory and practice of physic" was filled by Dr. John Morgan.

A brief consideration of the character and career of Dr. William Shippen, Jr., the first Professor of Anatomy and Surgery in America, may well detain us for a few moments. His father, Dr. William Shippen, was an eminent physician in Philadelphia, in which city the son was born, in 1786. Young Shippen graduated in 1754, at the College of New Jersey, of which institution his father was one of the founders. After studying medicine for three years with his father, he repaired to Europe, where he studied at Edinburgh and London. He returned to Philadelphia in 1762, in which year, at the age of twenty-six, he gave his first course of lectures on anatomy. One of his successors in the chair of anatomy — Dr. W. E. Horner — says: "Dr. Shippen seems to have been intended by nature to lay the corner-stone of the immense edifice of medicine, which has since been erected in this country. Aged twenty-six, at the period alluded to, uncommonly perfect in his form and engaging in his aspect ; his manners were those of a finished gentleman; his enunciation was fine; his temper invari- ably sprightly and good, could neither be excited by rancor, nor rendered sullen and morose by opposition. To the personal ad- vantages stated, and those of extensive hereditary friendship and family alliance, Dr. Shippen added foreign study — at that day all important in public estimation, from the want of opportunities of instruction here. While in London he lived in the family of Mr. John Hunter, the celebrated surgeon, and followed the lectures of Dr. William Hunter on anatomy and mid-wifery. He enjoyed the advantages of great intimacy with Sir John Pringle and Dr. Fothergill. To the incentive of such illustrious associations we may attribute much of the energy and determination which marked his subsequent career. Dr. Shippen arrived in Philadelphia in the Spring of 1 762, having completed his studies and gained from his preceptors the reputation of great natural talents."

THE STUDY OF HUMAN ANATOMY. 79

In the Pennsylvania Gazette, published by B. Franklin, Poet- master, and D. Hall, November 11, 1762, I find a card from Dr. Shippen which, inasmuch as I cannot find that it has been repub- lished, I venture to quote as a whole :

Philadelphia, November 11. Mb. Hall. Sir:

Please to inform the Public that a Course of Anatomical Lectures will be opened this Winter in Philadelphia for the Advantage of the young Gentlemen now engaged in the Study of Physic in this and the neighboring Provinces, whose Circumstances and Connections will not admit of their going abroad for Improvement to the Anatomical Schools of Europe ; and also for the entertainment of any Gentlemen who may have the Curiosity to understand the Anatomy of the Human Frame.

In these Lectures the Situation, Figure and Structure of all the parts of the Human Body will be demonstrated; their respective uses explained, and, as far as a Course of Anatomy will permit, their Diseases, with the Indications and Method of Cure, briefly treated of; all the necessary Operations in Surgery will be performed, a Course of Bandages exhibited, and the whole conclude with an Explanation of some of the curious Phenomena that arise from an examination of the Gravid Uterus, and a few plain general Directions in the Study and Practice of Midwifery.

The Necessity and public Utility of such a Course in this growing Country, and the Method to be pursued therein, will be more particu- larly explained in an Introductory Lecture, to be delivered the 16th Instant, at six o'clock in the Evening, at the State House, by William Shippen, jun., M. D.

N. B. The Managers and Physicians of the Pennsylvania Hospital, at a Special Meeting, have generously consented to countenance and encourage this undertaking; and to make it more entertaining and profitable, have granted him the use of some curious Anatomical Casts and Drawings (just arrived in the Carolina, Capt. Friend) presented by the judicious and benevolent Doctor Fothergill, who has improved every Opportunity of promoting the Interest and Usefulness of that noble and flourishing Institution.

The Pennsylvania Gazette, of November 25, 1762, contains the following announcement :

Dr. Shippen's anatomical lectures will begin to-morrow evening at six o'clock, at his father's house, in Fourth street. Tickets for the 9

80 E. M. HART WELL.

course to be had of the doctor at five pistoles each, and any gentlemen who incline to see the subject prepared for the lectures, and learn the art of dissecting, injections, etc., are to pay five pistoles more.

It is stated that his first class numbered twelve. "Having thus started, it is not to be understood," says Dr. Horner, "that the lectures proceeded without occasional interruptions from popular indignation; for .the city being small, almost everyone knew what was going on in it. The house was frequently stoned, and the windows broken; and on one occasion, Dr. Shippen's life was put into imminent danger. While engaged within, the populace assembled tumultously around the house. His carriage fortu- nately was at the door, and the people supposing that he was in it made their first attack there. The windows of the carriage being up, they were speedily demolished with stones, and a musket ball was shot through the body of the carriage; the coachman applied the whip to his horses and only saved himself and his vehicle by a rapid retreat under a shower of missiles. The Doctor hearing the uproar, ascertained its cause, and extricated himself through a private alley."

Possibly the riot above described by Dr. Horner, may have elicited the following utterance from Dr. Shippen, which is printed in the Pennsylvania Qazette, December 26, 1765:

It has given Dr. Shippen much Pain to hear that notwithstanding all the Caution and Care he has taken to preserve the utmost Decency in opening and dissecting dead Bodies, which he has persevered in chiefly from the Motive of being useful to Mankind, some evil-minded Persons, either wantonly or maliciously, have reported to his Dis- advantage that he has taken up some Persons who were buried in the Church Bnrying Ground, which has disturbed the Minds of some of his worthy Fellow Citizens. The Doctor with much Pleasure, improves this Opportunity to declare that the Report is absolutely false ; and to assure them that the Bodies he dissected were either of Persons who had wilfully murdered themselves or were publicly executed, except now and then one from the Potter's Field, whose Death was owing to some particular Disease ; and that he never had one Body from the Church.

In Chapter CCXI of the "History of the City of Philadelphia," written by Westcott Thompson, but not yet published in book form, are found the following statements regarding Dr. Shippen:

THE STUDY OF HUMAN ANATOMY. 81

"Late in November 1762, Dr. Shippen received the first subject for dissection of which there is any record. A negro man having cut his throat with a glass bottle, from the effect of which he died, the action upon his case is thus recorded by the Gazette of December 2. ' After the coroner's jury had pronounced him guilty of self murder, his body was immediately ordered by authority to Dr. Shippen's anatomical theatre/ this accession to the stock of the dissecting room must have been received a day or two after the opening lecture.

14 In September 1765, Dr. Shippen was compelled to deny publicly that he had taken dead bodies for the purposes of dissection from the church burying grounds. In September 1768, he was again obliged to contradict the rumor that he had taken dead bodies from