The Harveian oration 1873

by George Rolleston

THE HARVEIAN ORATION

1873.

BY

GEORGE ROLLESTON, M.D., F.R.S.,

LINACRE PROFESSOR OF ANATOMY AND PHYSIOLOGY,

AND

FELLOW OF MEETON COLLEGE, IN THE UNIVEESITY OF OXFORD.

London:

MACMILLAN AND CO.

1873.

OXFORD:

By E. B. Gardner, E. Pickard Hall, and J. H. Stacy,

PRINTERS TO THE UNIVERSITY.

Τί δόδ' ἄχνυμαι
φθόνον ἀμειβόμενον τὰ καλὰ ἔργα;
φαντί γε μὰν οὔτω κεν ἀνδρὶ παρμονίμαν
θάλλοισαν εὐδαιμονίαν
τὰ καὶ τὰ φέρεσθαι.

⁠Pindar, Pyth. vii. 19.

TO

GEORGE BURROWS, M.D., F.R.S., D.C.L.,

PRESIDENT OF THE

ROYAL COLLEGE OF PHYSICIANS OF ENGLAND,

WHOSE OWN ATTAINMENTS,

WHOSE SYMPATHY WITH THE INTELLECTUAL ACTIVITY

AND PROGRESS OF OTHERS,

WHOSE UNSWERVING DISCHARGE OF GREAT, AND WHOSE

CONSCIENTIOUS FULFILMENT OF DETAIL DUTIES,

FURNISHED FOR MANY YEARS A VALUABLE EXAMPLE

TO THE

STUDENTS OF ST. BARTHOLOMEW'S HOSPITAL,

THIS HARVEIAN ORATION

IS GRATEFULLY DEDICATED

BY ONE OF HIS FORMER PUPILS.

Oxford, 1873.

THE HARVEIAN ORATION

1873.

Mr. President and Fellows of the College of Physicians:—A man whose lot it is to live away from London may well feel some diffidence in accepting an invitation to lecture before a metropolitan audience; and, Sir, when you honoured me by requesting me to deliver this year's Harveian Oration, I felt and expressed this natural hesitation. I wish to record that you pointed out to me that my function in Oxford was to pursue and lecture publicly upon the very subjects with which Harvey occupied himself; and I suggested to myself that what could with any propriety form the substance of a course of lectures in the one place, could, mutatis mutandis, furnish materials for an address in the other. I felt besides, that, as the President of the College of Physicians is by virtue of his office one of the five electors to the Linacre Professorship, the Linacre Professor might seem scarcely justified in declining an invitation to appear before the learned body to which in part he owed his position; and, though I mention it last, I felt first of all that a wish expressed to me, not so much by the official whom I am now addressing, as by the individual who now more than twenty years ago introduced me to Harvey's hospital, and has persistentry befriended me ever since, was a wish which I ought not lightly to disregard. If now, Sir, I follow an example which you have often set me, and, without needless preface or further personal allusions, address myself at once to the business before me, I shall thereby pay you the best of all compliments, by showing you that your teaching has not been wholly thrown away upon your former pupil. The time allotted to me I propose to occupy, firstly, in expounding with all possible brevity certain advances recently made in our knowledge of the anatomy and physiology of the circulatory organs; and, secondly, in giving the as yet unrecorded history of one of the many attempts to rob Harvey of his rightful rank in the noble army of discoverers, which were made in the latter half of the seventeenth century.

Some of the last, if not the very last, of the many fruitful experiments which Harvey performed in the way of interrogating Nature as to the circulation, were experiments in the way of injection. If the writer of a work which appeared but some forty-three years ago, On the Diseases and Injuries of Arteries^[1], had taken the pains to repeat those experiments which Harvey performed more than two hundred and twenty years ago, and when in his seventy-fourth year, we should not have had the following statement at page 9 of his book : 'I have conceived that the arteries contain air in an uncombined state, which may assist in keeping them distended, and in facilitating the circulation; but I have not been able to prove it.' The fact that Harvey performed experiments in the way of injection may be unknown to many persons who are too well informed to conceive that the arteries may or can, compatibly with the carrying on of any circulation, contain air in an uncombined state; for these experiments are not to be found recorded either in the treatise De Motu Cordis or in either of the two letters to Riolanus; which two compositions were, in the older editions of Harvey's works, printed as three parts of a single treatise, under the names of ' Exer-citatio Anatomica i. De Motu Cordis, etc.,'Exercitatio Anatomica ii. De Circulatione Sanguinis,' and 'Exercitatio Anatomica iii. De Circulatione Sanguinis'; and were, till the appearance of the College of Physicians' edition in 1 766, the only published^[2], as they are still the best-known, records of Harvey's work and labour upon the circulation of the

preceding it, received three letters from Harvey. By consulting Horstius' work referred to by Dr. Akenside, l. c, I found at pp. 61-65 the letter, which appears in our edition as ' Epistola Tertia responsoria Morisono,' published by Horstius in 1656 with the omission of the first six and a half, and also of the last three and a half lines. These lines Harvey had doubtless ordered his amanuensis—a functionary of great importance to one who wrote so bad a hand (see p. 165, ed. 1766, or Harvey's own autograph MS. No. 486, Sloane Coll. British Museum)—to omit when he bade him copy and send to Horstius, 'eadem quae antea medico cuidam Parisiensi (sc. Morisono responderat.' Horstius does not publish Harvey's letter (the 'Epistola Quinta' of our edition) of date Feb. 1, 1654-5, but appends the last letter of the three (the 'Epistola Sexta' of our edition) to his own answer to Harvey's earlier communication. I shall henceforward refer to the College of Physicians' edition of Harvey's works as 'ed. 1766,' and to Dr. Willis' most valuable translation of them, published by the Sydenham Society in 1847, as 'ed. "Willis.' I throw out as a topic for future discussion the question whether Dr. "Willis is right in following the editions of Harvey's writings of an earlier date than 1766, in retaining the negative in the sentence (at p. 131 in both his edition and in that of 1766) in the second epistle to Biolanus which refers to the Critias of Plato. I think Dr. Willis is right, and that Dr. Lawrence was wrong; but to do this it is necessary to sacrifice Hai-vey's credit for knowledge of Plato whilst vindicating the consecutiveness of his reasoning. Harvey himself blood. The experiments to which I refer are put upon record in a letter of Harvey's to P. M. Slegel, of date 1651 (see Harveii Opera, ed. 1766, p. 613; ed. Willis, p. 597). They were undertaken with the object of giving a final and happy despatch to all the quibbling objections of Riolanus, 'omnes Riolani circa hanc rem altercationes jugulare;' and they consisted, firstly, in forcing water from the cava into the right ventricle whilst the pulmonary artery, the 'vena arteriosa' of those days was ligatured—whereby Riolanus' suggestion as to the permeability or porosity of the interventricular septum was shown to be untenable; and, secondly, in forcing water from the pulmonary artery round into the opened left ventricle, whereby the lesser circulation was demonstrated, to use Harvey's own favourite word, αὐτοψίᾳ; or, to use the very words employed by him upon this very oc-

would probably have accepted this alternative. It is right to add, however, that so far as ray reading of the edition of 1766 has carried me, I have come upon no other case where I have been forced to think that Dr. Lawrence may have blundered. casion, by an 'experimentum ἄφυκτον a me ' (in his seventy-fourth year) 'nuper et collegis aliquot praesentibus exploratum.' Simple as this experiment may seem to us now, I do not think that any apology is required for the drawing of attention to it; for it is only twenty-eight years ago (see Edinburgh Medical and Surgical Journal, vol. lxiii. p. 20), that Dr. Sharpey, to whom our Baly Medal has been so recently and so fitly assigned, had to perform the very closely similar experiment of injecting defibrinated blood into the thoracic aorta, with the very closely similar object of showing that the force of the heart was sufficient to account for the passage of blood through the intestinal and hepatic vascular systems—nay, to perform an all but identical experiment, adding on to it but the means for estimating and reproducing the force put out by the ventricle concerned. If such experiments as these were necessary in 1845, how much more necessary must have been the still simpler experiments of Harvey in 1651! At that time, the prestige of Eiolanus the younger 'pressed heavily upon mankind.' Harvey himself had called that individual 'anatomicorum coryphaeum' in 1649; and, in the very year and letter we are dealing with, he calls him 'celebrem anatomicum.' And Pecquet, the discoverer of the thoracic duct, in his work, also of this selfsame year 1651, the Experimenta Nova Anatomica, a work spoken of by Haller (Bihliotheca Anatomica, i. p. 443) as 'nobile opus et inter praecipua saeculi decora,' has the following remarkable passage : 'Ita sentiunt non vulgaris peritiae medici Harveius, Veslingius, Conringius, Bartholinus, aliique complures; nee melior ipse Joannes Riolanus (quod mirari subit pro eximia viri, qua in rebus anatomicis caeteros anteivit sagacitate). Audi hanc in rem illius sententiam.' p. 4, l. c. This, I think, I will spare you; but I will remark that, after this singular—or perhaps, alas! not singular—instance of the blundering judgments which contemporary writers may pass upon each other, no young man, nor indeed any old one—for Harvey was in his seventy-fifth year when he first read Pecquet's work (see Ep. Tert. p. 620, ed. 1766; p. 604, ed. Willis)—should overmuch fret if his own age, in his own estimation, do him scanty justice. Posterity ordinarily—I do not say always—rectifies these false judgments; it has done so, at all events, in the cases of the men so grotesquely grouped together by Pecquet^[3] . Haller, for example, writing in 1774 (Bibliotheca Anatomica, i. p. 301), speaks of Riolanus as 'vir asper et in nuperos suosque coaevos immitis ac nemini parcens, nimis avidus suarum laudum praeco, et se ipso fatente anatomicorum princeps.' The duty of attacking and abolishing such a man may, or indeed must have been, a disagreeable one to his contemporaries. They appear to have shirked it : it was their duty to have faced it, notwithstanding it might have been disagreeable.

Harvey used for these experiments a somewhat rough injecting apparatus, ' quem-admodum in clysteribus injiciendis fieri solet' (p. 614, ed. 1766; p. 597, ed. Willis). The modern experiment which I wish first to introduce to your attention, rests for its accomplishment upon the employment of the delicate injection-syringe (for Einstichung) of Ludwig, and of the fine soluble Berlin blue for the substance to be injected. Here, as in many other instances, our superiority to our forefathers rests mainly or wholly upon our possession of more delicate, or upon our command of more powerful agents; and the delicate syringe and the penetrating soluble injection-mass help us to discoveries and demonstrations impossible in default of such means; just as the superior lenses of Malpighi and Leeuwenhoeck helped them to the discovery and demonstration of the capillary circulation, unknown to the discoverer of the makroscopic circulation. The experiment to which I refer has its results fairly represented in the accompanying drawing Fig, 1) of a specimen prepared by

myself at a class-demonstration. It gives a figure of the lacteals injected, by the means just specified, as they exist upon the terminal segment, here widely globular, of the ileum,

Fig. 1.—Vermiform Appendix, Caecum, and parts of Small Intestine and Colon of Rabbit (Lepus cuniculus), with the Peyerian and also some of the mesenteric glands in connexion with them injected. The ileum and colon lie side by side, the former describing a siphon-shaped curve before ending in a dilatation, known as the 'sacculus rotundus,' and homologous with the aggregation of Peyerian follicles situated in man just anteriorly to the ileo-caecal valve. The sacculus rotundus occupies the centre of the figure; above and a little to the left of it another somewhat similar aggregation of Peyerian follicles is seen just beyond the ileocolic valve. The colon curves backwards externally to and concentrically with the ileum. The caecum consists of two portions: one larger in calibre, thinner in walls, and sacculated spirally; the other, the homologue of the human 'appendix vermiformis,' smaller in calibre, but with much thicker walls. It has been injected as described in the text, and the injection is seen to have passed into some mesenteric glands situated close to the junction of the two segments of the caecum, and between it and the colon.

upon a single disciform patch upon the commencing colon, and, finally and chiefly, upon and all around the walls of the colossal vermiform appendix of the rabbit. In this latter place it is but what the Germans call, and have called (Frey, Das Mikroskop und die microskopische Technik, 4th ed. 187 1, p. 255), a Kinderspiel, to insert the point of the fine Einstichung syringe charged with the soluble blue injection just beneath the peritoneal coat at the caecal end or elsewhere, when, upon pressing the piston, a reticulation of blue will spread itself over the surface of the tube, enclosing as islands the solid substance of the Peyerian follicles. It needs but a little perseverance in the way of gentle pressure to cause superficial tubular lymphatics to arise into view, and to declare their true character by their contrast with and distinctness from the blood-vessels, as well as by their moniliform character speaking of their richness in internally placed valves. Passing over the convex walls of the appendix, they join larger trunks which run along its mesenteric border; these larger trunks in their turn enter the mesenteric glands, and form in their substance reticulations strikingly like those formed previously in the walls of the intestine around the solid substance of the Peyerian follicle—suggesting thus to the naked eye the similarity, and by consequence the homology, which a microscopic examination enables us to prove to exist between the lymph sinuses and the solid masses they surround in the Peyerian follicles and in the mesenteric glands respectively ^[4].

It is the demonstration of the relation of the lymphatic or lacteal vessels, or sinuses, as the case may be, in different animals, to the solid ampulla-like masses in the Peyerian follicles, which the modern method of puncture can claim as being eminently its own attainment; for many years ago—in 1784, in fact—and three years before the appearance of Mascagni's splendid work, with similar figures and histories of similar experiments (Vasorum Lymphaticorum Historia et Iconographia, 1787), the continuity of the lacteal radicles upon the walls of the intestine with the 'lymph-paths'—to borrow a word of later coinage—in the mesenteric glands, and finally, after passing through successive lines of these apparently solid structures, with the thoracic duct itself, had been demonstrated by Sheldon, then Professor of Anatomy in our Royal Academy of Arts. These are his words (from p. 49 of his work, Of the Absorbent System, 1784), describing his plate No. 5, a copy of which I have had made and suspended here: 'In the fifth plate of this work, upon a portion of human jejunum from an adult female subject, seventeen lacteal vessels are injected with quicksilver, by inserting pipes into them upon the intestine. They were remarkably large and varicose in this subject, and as the quicksilver was poured into the lymphatic injecting-tube to fill these vessels, it frequently ran out in a full stream by the jugular vein, which was opened. This circumstance rendered it evident that the mercury had passed through the whole course of the lacteals and thoracic duct, and had penetrated even into the venous system. It is, I believe, the only instance in which the thoracic duct has been injected from the lacteals on the intestines e

e I have some pleasure in pointing out that by making a reference to the plates of the venerable Professor Arnold, Fasc. i. Tab. i. fig. 2, 1838, it may be seen that the quick-silver injection could sometimes give as correct results as the 'silver method' of modern microscopy for the detection of lymphatics by their epithelium. The figure I refer to shows the fourth ventricle plexus without, the velum interpositum, on the contrary, with, lymphatics injected with piicksilver. The use of the silver method has enabled me to prove that this representation is correct: abundance of choroidal villi can be procured, and very beautiful objects they are when treated with 0.25 per cent, solution of nitrate of silver, from the plexus in the fourth ventricle, but no lymphatic vessels. These can be shown from the velum interpositum by the use of the same reagent. The use of puicksilver as an injection-substance has not always led as happy results as in the instance just given. Not to specify other cases, it is curious to note that the penetra Sheldon's first plate, I may add, when compared with his letter-press on p. 37, appears to show that what he calls 'ampullulae' were really Peyerian glands, and that he had repeatedly seen these glands distended in the way of natural injection with chyle, as it is easy enough to see them distended in an animal, such as a rat, which can be got to feed on fatty food, and can be killed at a proper interval of time afterwards. He appears to have had very serious as well as reasonable doubts as to the existence of any foramen in the apices of these 'ampullulae'; but the authority of Lieberkuhn, whose Dissertatio Anatomica (p. 18) he had himself edited, appears to have weighed with him more than his avTojria. Near, therefore, as Sheldon came to seeing the whole truth, he just failed of

tion of this material into the parieto-splanchnic ganglion of the Lamellibranchiata when thus employed by the skilful Italian anatomist, Poli, and its distributing itself thence into the nerves given off from it by displacement of their granular neurine, seduced him into supposing these structures to constitute a lymphatic system, 'cisternam lacteam et vasoruni lactiferorum surculos.' See Testacea Utriusque Siciliae, torn. i. p. 39, 1791. doing so entirely and completely; and the views which Lieberkiihn had put forward (p. 10, loc. cit.) as to the great number of the Peyerian glands in the lower segment of the small intestines, being a proof that they held relation to secretion or excretion rather than to absorption, prevailed and have prevailed, even into our own day. These are Lieberkiihn' s words: 'Quare ad finem ilei plures quam in integro intestino positi erunt? Nonne propter faeces jam-judum exsuccas et indurescentes ut lubricatae valvulam facile transeant nee laedant?' In Henle's ordinarily and marvellously excellent Generelle Anatomie, of date 1841, I find (p. 895) the excretory character of the Peyerian follicles taken as something certain; the only thing left uncertain being the question as to whether their contents found their way into the cavity of the intestine by a constantly patent, however small, duct, or by dehiscence, as ova from an ovary. In 1850 the real meaning, the true physiological import, of these glands was proved by Briicke. The method of injection, of which I have spoken, enables us to demonstrate or exhibit what was then proved, and that with the greatest ease. It is difficult to understand how any one can now doubt that the Peyerian glands are really but the pileorrhizae of the roots, the glands the tubera and the thoracic duct the trunk or stem of the absorbent tree.

If any apology be needed for my dwelling so long upon a point of anatomy which has not merely much historical, but also much practical, interest—the Peyerian glands being the part of the organism especially affected by the poison of typhoid fever, which I see has, amongst other aliases, that of 'Peyerian fever' (Walshe, On Diseases of the Heart, 3rd ed. p. 208)—I would add that I was till recently under the impression that the actual demonstration, the doing, of that which my Fig. 1, p. 17, represents as done, might have been a fitting exhibition for me to go through upon the present occasion, following herein the example of Harvey, 'viliora animalia in scenam adducentis.' I have, however, learned that this very demonstration on the appendix vermiformis of the rabbit has been often performed in Germany, and, indeed, also in England; and I judged, consequently, that it might be superfluous, as it would not be novel, to exhibit it here and now.

Having been thus disappointed in my intention of demonstrating something new in this direction, I cast about in another for something of the same character. And in the heart of a bird, the Australian Cassowary (Casuarius australis), killed at Rockingham Bay, lat. 18 deg., on the east coast of that continent, and sent me by my former pupil, J. E. Davidson, Esq., I came upon a structure which I am well assured has never been either described or figured before. It possesses upon this ground some claim upon our attention; but it possesses stronger claims than any which mere rarity could give it, being a structure which, though it has never been seen in any other member of

the class Aves, is largely developed, and, indeed, exactly reproduced in the hearts of certain mammals, and does not fail to be represented, at least rudimentarily, in our own. The structure in question is a 'moderator' band, holding precisely the same

Fig. 2.—Heart of Sheep. The right ventricle is laid open. The letter M indicates the moderator band. A probe has been passed between the chordae tendineae, passing from a musculus papillaris arising from the movable wall of the ventricle to the two main segments of the tricuspid valves and the outer wall of the ventricle.

27 relations to the other parts of the right ven- tricle in this bird which the band so named by Mr. T. W. King in the Guy's Hospital Reports, vol. ii. p. 122, 1837, holds in many, if not in all, Ungulate mammals. This, I presume, is made plain by a comparison of the two diagrams (Figures 2 and 3) show- ing, one of them the heart of this bird, the other the heart of a sheep, with the right ventricle similarly laid open in each case. The advantage, which in the struggle for existence, and specially in that very com- mon phase of it which takes the form of a race for food or from an eater, which an animal with such a muscular band passing directly across the cavity of its right ven- tricle from its fixed to its movable wall must possess, is not a difficult thing for any man to understand who has ever either watched in another or experienced in himself the dis- tress caused by the over-distension of any muscular sac f . A band of similar function f Since writing as above I have been reminded of what I ought not to have forgotten, viz. that my friend Dr. Milner Fothergill has discussed this very subject in his work, The Heart and its Diseases with their Treatment,

London. 1872, p. 6.

Fig. 3.—Heart of Australian Cassowary (Casuarius australis), prepared similarly to the heart of sheep, figured in Figure 2, and showing at M the moderator band. A line of papillary upgrowths are indicated at the upper end of the upper segment of the muscular auriculo ventricular valve, passing downwards towards the point of origin of the moderator band from the septum. They extend in the specimen over a space of about three-eighths of an inch, and are indicated in the woodcut by dark transverse lines.

29 — I do not say definitely of precisely the same morphological importance — has often been figured as existing in the hearts of most or all Reptilia below Crocodilina ; and it serves in them to close up and expel the blood from the pulmonary compartment of their imperfectly divided ventricle. Such being the function of this moderator band, what is its morphological bearing, and what traces can we find of it in ourselves, tempting us to speculate as to the nature of the secret bond which brings us into rela- tions of affinity not only to the mammalian class, but with an older stock, the many- sided potentialities of which embraced not only mammals, but all warm-blooded animals, and not only all warm-blooded creatures, but warm-blooded animals and reptiles also? The valves of the heart in the higher vertebrata, when regarded from this point of view of development — the safest if not the sole cri- terion of homology — may be spoken of as being but trabeculae flaked off from the inner surface of the wall of a muscular sac, and subsequently made more or less membran- ous in the way of specialisation and its 30 correlative economy. Thus, as Gegenbaur (Vergleichende Anatomie, 2nd edition, p. 836) has remarked, the intervalvular space in these animals corresponds to the entire cavity of the spongy walled heart of fishes and amphibia; and the sinuous intertra- becular cavities in the spongy walls of these latter animals correspond with the chief part — viz. the extravalvular part of the ventricular space — in mammals, birds, and Crocodilina. Now,. the musculi papillares represent the disposal or destination of the innermost layer of the right ventricle, ac- cording to Dr. Pettigrew (see his paper, Phil. Trans. 1864, p. 479); and I would submit that the moderator band is but a specialisa- tion of the next layer in order from within outwards — to wit, Dr. Pettigrew's sixth layer, which he has figured (Plate XIV. fig- 33) as proceeding in a spiral direction from right to left, much as the fibres of the moderator bands I have figured do. A study of the heart of the rabbit will put this matter in a very clear light, and further open our eyes to see and recog- nise the rudimentary representation of this 31 moderator band in our own hearts. If we look at the outer aspect of that very constant musculus papillaris, which passes in man from the outer and movable wall of the right ventricle to distribute its chordae tendineae to the two more anteriorly placed of the three segments of its auricular valve, we shall frequently see that its longitudinal fibres are crossed nearly or quite at right angles by a slender fibrous band, so that we have before us an appearance not wholly nor essentially unlike that presented by the striae longitudinales of Lancisi and the fibres of the corpus callosum when viewed in their mutual connexion. This band of fibres can sometimes be traced up towards the conus arteriosus, and be seen not to die away until close upon the point of origin of the most anteriorly or upwardly placed of the chordae tendineae which arise from the septum to pass to the hindermost of the three segments of the tricuspid. The points between which this line of fibres lies may be observed to be the very same as those between which the moderator bands in the Cassowary and

the Sheep stretch as free columns in the

Fig. 4.—Human Heart. The right ventricle has its cavity exposed. The moderator band M is seen to pass up from the base of a musculus papillaris arising from the outer or movable wall of the ventricle into the neighbourhood of the conus arteriosus. Close to this, its upper end, a chorda tendinea arises by two roots, and passes up to the most posteriorly placed of the three cusps of the tricuspid valve.

33 diagrams before you. It is not altogether rare to see this band raise itself from the position of fusion, like the ventricular wall, and assume the character of a cylindrical band for a lesser distance, but with no less distinctness as a column, than in the Un- gulata. Such a case I had actually before me whilst writing this, and you have it now figured before you (Fig. 4) s. Every gradation, in fact, exists between the entire obsolescence of the moderator 8 Since this oration was delivered I have received two communications relating to the presence of a moderator >and in the human heart. One of these, from my former jupil, J. C. Galton, Esq. F.L.S., was accompanied by a sketch in which a moderator band was drawn as passing in a human heart from the insertion into the movable wall of the ventricle and the very constant musculus papillaris supplying what I would call the 'conad' and ' dextrad' cusps of the tricuspid, to an origin on the inter- ventricular septum, sending a root up to the point of origin of one of the chordae tendineae of the third cusp, called 'septal' by Mr. Galton. See also Mr. Galton's setter to British Medical Journal, July 26, 1873, p. 83. I have to thank Dr. Headlam Greenhow for a reference another notice of the presence of a moderator band in human heart. It will be found in an interesting paper his in the Transactions of the Pathological Society, )1. xxi. 1870, p. 88. D 34 band, which we sometimes see in the human heart, through the typical, and I should an- ticipate, constant, but not functionally im- portant, representation of it in the rabbit, up to the important and structurally promi- nent development attained to by it in the Ungulate mammal, and this solitary instance for the class of Birds, and the sub-class with such generalised affinities, of Struthiones. And, speaking of the method of gradations, I take this opportunity of saying that its application in the case of the muscular right auriculo-ventricular valve of birds will, in my judgment, put an end to the disputes which have taken place as to its homology with one or other of the two valves in the crocodiles. The two portions of the valve in the Casuarius australis are so nearly equal — the larger being 17 inch, as against 1 4 of the smaller — as to do away with the difficulty which might be felt in holding that both Crocodilian valves are represented here. There are other reasons for this view, which I reserve for another occasion. But whilst speaking of the heart of the Bird, I cannot forbear pointing out how the structural ar35 rangements of its auricle, differing as they do strikingly from those of the same com- partment in the mammalian heart, help us by that contrast to get a true idea of the working of this latter. ' Firstly, the walls of the Bird's right auricle are relatively thicker, not only as compared with the walls of its own ventricle, but also as compared with the walls of the corresponding auricle in the Mammal, the musculi pectinati standing out in as sharp relief as the similarly working muscular ridges in a hypertrophied bladder, and inclosing anfractuosites and recesses almost as deep. But, secondly, and what is of more importance, the Bird's auricle is furnished with a large and functionally ac- tive valve, protecting the entrance of the great veins, and preventing regurgitation into those vessels just as the auriculo- ven- tricular valves prevent regurgitation from the ventricles. It is fair to argue a priori that if the Mammalian auricle had counted for as much in the action of the heart as the Bird's, its force would have been economised by the placing of a large and functionally useful valve in the site of the rudimentary D 2 36 Eustachian — a structure altogether absent in many mammals, and variable, as rudi- mentary structures very often are, in our- selves. The d priori argument of Com- parative Anatomy is abundantly borne out by the appeal to experiment. Marey, in his ' Physiologie Medicale de la Circulation du Sang,' 1863, whilst referring (p. 36) to other evidence from Comparative Anatomy than that which I have adduced, cites, in support of the view that the auricle has but an accessory and subordinate role in the func- tions of the heart, an experiment of Chau- veau's, in which the auricle of a horse, being exposed and irritated, lost its contractile power for a time, during which, neverthe- less, the ventricles continued to contract and the circulation to be maintained. Colin, again (Traits de la Physiologie Comparee, vol. ii. p. 257, 1856), found that the left ventricle continued to be filled with blood even when the corresponding auricle was prevented from contracting by the insertion into it of a finger. And further, Magendie had long ago noted, in experimentation, what many here present may have noted 37 in pathological or clinical observation — viz. that the auricles may remain extremely distended for hours, and, like other mus- cular sacs similarly conditioned, unable to contract and empty themselves, without the circulation for all that being brought to a standstill. It was Dr. Pavy's paper, treat- ing (in the Medical Times and Gazette of November 21, 1857) of the case of a man (E. Groux) with a congenital fissure of the sternum, which first drew my attention to these points ; and his summary of what takes place in the dog is so clear that I herewith reproduce it. ' In the dog, the contraction of the ven- tricl es is sharp and rapid, instead of p ro- longed, as in the reptile, and does not app ear to occupy ne arly so much time as half the period of the heart's action. Thj> ventricular contraction communicates a sudden impulse to the auricles, occasioning in them a dis- tinct pulsation, which is instantly followed by a peculiar thrill, wave, or vermicular movement, running through the auricular parietes down towards the ventricle. This thrill or wave is coincident with the passage 38 of the blood from the auricle into the ven- tricle, and takes place so instantaneously after the ventricular contraction, that the one movement appears to run on to continue itself into the other. There is then a pause, which seems comparatively of considerable duration, and which is succeeded by a re- commencement of the heart's action, begin- ning with the ventricular contraction.' Dr. Pavy has very kindly gone to the trouble of repeating the experiment upon which these statements are based ; and from a letter with which he has favoured me, I gather that the auricular contraction detectable by the cardiography tracing, as immediately preceding the ventricular con- traction, is also detectable, of course during the pause just mentioned, by the eye, un- assisted by the cardiograph, and turned simply upon the exposed heart, in which the auricular appendix is seen to become redder or more flesh-coloured at the moment in question. And he further remarks that this auricular contraction, difficult 11 though h I apprehend that Dr. Walshe's account of the auscul- tatory phenomena as occurring under normal conditions

39 it be to be observed under physiological conditions, may be exaggerated into con- siderable prominence in disease entailing contraction of the auriculo-ventricular ori- fices, and may then make itself known by a presystolic murmur. I should now be glad to draw attention shortly to a few memoirs which have ap- peared comparatively recently, and which treat of matters of considerable interest, not merely as scientific problems, but also as practical questions. First among these I would name the paper which appears in the third volume of Professor Ludwig's 'Ar- beiten/ 1868 (having previously appeared in vol. xx. of Bericht Math.-Phys.-Klass. K. S. Gesellsch. Wissensch., Leipzig), by Professor Ludwig himself and Dr. Dogiel. In this paper we have a number of experiments recorded as performed with the hearts of dogs removed from the body, and as nearly will be accepted as correct. It runs thus (Diseases of the Heart and Great Vessels, 3rd ed. 1862, p. 65): 'In the normal state the blood enters the ventricles from the auricles with a curi'ent so calm as to prevent audible sound from being thereby produced in the former cavities.' 40 as possible emptied of blood ; and the con- clusion which the authors come to is that the heart of the dog, when removed from the body and emptied of blood, still pro- duces a sound during the systole of the ventricles which is not essentially different from that which is recognised as the normal first sound of the heart. The authors add, however (p. 85), that they do not think these experiments entirely exclude the possibility of the tension of the auriculo-ventricular valves entering as a factor into the produc- tion of the first sound ; and hereby they would be guarded from coming into con- tradiction with most English authorities — as for example, Dr. Walshe (Diseases of the Heart, 3rd ed. 1862, p. 62). Dr. Guttmann, however, in a paper of no great length, but of considerable merit, published subsequently to the one just mentioned, and in Virchow's Archiv for 1869, points out with much acuteness what, when once pointed out, is ever thereafter obvious — viz. that it is, in the nature of things, impossible, with all possible precautions in the way of emptying the heart of blood, to empty the complex 41 phenomenon made up by a systole of the heart of the condition of tension of the auriculo-ventricular valves. Surely the mus- culi papillares will contract with the rest of the ventricular walls, and, contracting, will they not stretch the chordae tendineae and the valves'? For myself, I would say that we are more likely to overrate the share taken by the valves than to underrate that taken by the muscular walls. I need not say to this audience that the fact with which we are all familiar, of the alteration in the first sound produced by disease of the auriculo-ventricular valves, does not absolutely prove that they produce any part of it during health ; and, finally, to my own ear at least, a modification of Wollaston's experiments, which anybody can try for himself by making his temporal and mas- seter muscles contract at any time of perfect stillness, appears to produce a sound which is scarcely, if at all, different in quality from the first sound of the heart. A judgment, however, upon the nature of a sound, or, indeed, an aggregation of sounds, as in music, is one upon which two observers may 42 very well differ, as neither of them can lay his proof of supposed identity or difference alongside of that which the other may pos- sess, or may suppose he does. It is with much pleasure that I refer to Dr. Rutherford's paper on the Influence of the Vagus on the Vascular System, which appears in the Edinburgh Royal Society Transactions for 1870, vol. xxvi. In that year, having to deliver an address to the Biological Section of the British Association at Liverpool, I made bold to say that the results to which Dr. Rutherford had come, and which were then only known to me in an abstract in the Cambridge -and Edinburgh Journal of Anatomy and Physiology (May 1869, p. 402), would prove to be of the highest value and importance. His memoir now published in extenso, and extending over forty- two pages, as fully justifies my predic- tion as it will fully repay any one who will take the pleasant trouble of reading it. The most important result in a practical point of view is the demonstration which Dr. Ruther- ford has given of the nerve-circle, whereby, in the way of reflex action, the all-important 43 secretion of gastric juice is called forth. The sensory impulse caused by the ingestion of food into the stomach, is propagated upwards by the vagi to the medulla oblongata, where it throws into abeyance the vaso-motor nerve- cells, which, whilst the stomach is empty, keep the blood-vessels of the gastric mucous membrane constricted, but which, when their activity is inhibited, allow the zonular fibre- cells of these blood-vessels to dilate, and allow the increased afflux of blood thus called for. That relief will result to some of the countless martyrs to dyspepsia out of the demonstration of this physiological relation of vagus, sympathetic, and peptic glands, I do not doubt, Possibly, I would add, Owsjannikow's observations as to the working of hydrate of chloral as a depressor of arterial tension (Ludwig's Arbeiten, 1872, p. 32) may prove valuable to persons en- gaged in practice, by pointing out, in how- ever shadowy a fashion, the road to a more rational and systematised, even if less general use of this drug than that which I am told is now made of it. It may seem a paradox, but it is none the less true for all that, to say that, 44 for the activity of many organs, a paralysing and inactivity of certain nerve-centres in con- nection with them is a prerequisite. The ac- tivity of such, indeed of most, organs is but intermittent and occasional, being but inter- mittently and occasionally called for, whilst the constringing activity of the sympathetic has to be constantly at work to prevent waste of force i. Owsjannikow's paper (also to be found in Lud wig's Arbeiten, 6th year, 1871, and in the Bericht Math.-Phys.-Klass. K. S. Gesellsch. Wissench., Leipzig) just referred to, and pub- lished two years subsequently to Dr. Ruther- ford's, gives, as the result of a number of experiments performed in Professor Ludwig's laboratory at Leipzig on rabbits, and inde- pendently at St. Petersburgh on cats, the con- clusion that the ganglionic centres of inner- 1 The phenomenon of the distension of the corpora cavernosa, a phenomenon used by Harvey himself in the way of illustration (p. 129 of the Epistola Secunda ad Riolanum), I may adduce in the way of illustration also, being, as it is, dependent upon a similar nervous me- chanism; and being shown so unmistakeably, in cases where it follows lesions in the nuchal region, to result from paralysis of nerve-centres situated there or thereabouts. 45 vation for the entire sympathetic system occupy but a small space at the base of the brain, two strips to wit, one on each side of the median fissure in the floor of the fourth ventricle ; of, in the rabbit, a length of about four millimeters, beginning about four or five millimeters anteriorly to the calamus scriptorius, and ending about one or two millimeters behind the level of the corpora quadrigemina. The title of such a book as Eulenburg and Guttmann's Die Pathologie des Sympathicus auf Physiolo- gische Grundlage (Berlin, 1873,) is an en- couragement to those who hope to see fruit arise from such researches as these in the way of additions to our means for meeting, or at least understanding, human disease and suffering. It has long been known (Budge, 1855) that the sympathetic nerves which supply the vessels of the head and iris do not pass directly or by the shortest possible route to this their distribution, but pass down the spinal cord for a greater or lesser distance, and then turn outwards, and pass from the anterior nerve-branches to bend upwards, 46 much as the recurrent laryngeal nerve does. That other vascular regions receive their vaso-motor supply by this apparently cir- cuitous and, till the history of development is taken into consideration, paradoxical route, is from time to time being demonstrated. Dr. Pavy, to whom I have already referred, many years ago identified and mapped out one segment of the road along which nerve- force passes to the liver and prevents or allows the occurrence of diabetes. Fur- ther exploration of this route we owe to Cyon and Aladoff (Bulletin de l'Acade'mie Imperiale des Sciences de St. Petersburg, torn, xvi, p. 307 ; British Medical Journal, December 23, 1871); and this same investi- gator, working still in the same line of investigation, as it is in these days usually necessary for an investigator to work if he will make himself a name as a discoverer, has also shown us (Ludwig's Arbeiten, 3rd year, 1868) the track along which the vaso- motor nerves of the anterior limbs pass, proving that these nerves pass down in the spinal cord as low as the mid-dorsal region before leaving it to turn upwards in 47 the sympathetic chain to join the brachial plexus. Of all the results, however, which have been attained to in the line of experimenta- tion now under consideration, those come to by Brown -Sequard and demonstrated by him at the . meeting of the British Associa- tion held at Liverpool in 1870, and subse- quently published in the Lancet of January 7, 187 1, seem to me to be certainly the most striking and possibly the most important. Could anything have been more surprising to him whose memory we here this day commemorate, than to have been told that an injury to a particular part of the brain, the pons, called after the excellent anatomist whose life ended in the very year in which his had begun, would produce haemorrhage in certain parts of the lungs, and anaemia, oedema, and emphysema in others ? This is an easy experiment to repeat; it is one which might have been done in the days of Harvey as easily as in those of Bernard, of Budge, of Ludwig, and of Brown- Sequard. But easy though it would have been to perform, I am bold to say it was well for 48 Harvey that he never happened to per- form it. For considering that, like Hal- ler, he knew nothing of the contractility of arteries ; considering that Hunter had not performed his now well-known experiments with the umbilical arteries ; considering, Sir, that in that excellent work on Physio- logy Dv Johannes Muller, the translation of which in 1838, by our late and never suffi- ciently to be lamented friend Dr. Baly, we owe to your suggestion, I find several pages (vol. i, pp. 202-206, 214-219, ed. 1840) devoted to disproving the muscular con- tractility of arteries; considering, that it was not till three years later, in 1841, that Henle's work, already referred to, ap- peared with its still unsuperseded figures, Plate III, figures 8, 9, and 10 of the arteries with their circular muscular coat, and with its excellent summary in letterpress of the whole subject, pp. 518-526, and especially pp. 524, 525; when I consider that nothing of all this had been done, to leave unmen- tioned other advances connected with names of men yet living to speak for themselves and for us — I say it may have been well that Harvey never came upon the facts relating to the alterations of lung-substance being entailed by destruction of brain-substance, not difficult to be observed and reproduced, which we owe to Brown-Séquard, For if he had come upon them, how could he have explained them in the absence of the entire chain of connecting facts, in the forging of which chain so many successive workers—Purkinje, Valentin, Weber, Burdach, Stilling, and others—have all contributed links? Might not even Harvey, often as he withstood such temptations, have, nevertheless, in default of power to assign the real causes of such a phenomenon, been driven back upon some of those explanations which he himself so forcibly denounces in the words (Epistola Secunda ad Riolanum, p. 116), 'Vulgo scioli cum causas assignare haud norunt dicunt statim a spiritibus hoc fieri et omnium opifices spiritus introducunt, et ut mali poetae ad fabulae explicationem et catastrophen θεὸν ἀπὸ μηχανῆς advocant in scenam.' It is a hard thing for any man to abstain from speculating as to the cause of any well-established phenomenon, especially 50 if it be of striking interest and importance ; it is a hard thing for any man to do more than keep pace with his own generation ; and those who have spent any time in read- ing the works of Harvey's contemporaries, will best appreciate the difficulty he must have had in setting himself free from the influence of the idola theatri referred to. I pass from this reflection to an exposi- tion of the claims which have been put forward on behalf of Walter Warner, the editor in 1631 of Harriott's Algebra, to the discovery of the circulation of the blood ; and I do this by a natural transition, Walter Warner having been a man in whose mind, all his mathematics notwithstanding, the idola in question greatly abounded. War- ner's claims are alluded to by Dr. Willis in a note to his excellent Life of Harvey (see p. lxiv). They are put forward by Anthony Wood, upon the authority of Dr. Pell, a man distinguished as one of Oliver Cromwell's diplomatists, and afterwards as an assiduous supporter of the then young Royal Society ; and upon that of Dr. Morley, some time Dean of Christ Church, and afterwards Bishop of 51 Winchester (see Wood, Athenae Oxonienses, vol. i. p. 461, 2nd ed. 1 72 1 ; vol. i. p. 302, ed. Bliss). Aubrey, a contemporary of Wood's, appears, from a note at p. 417 of the second volume of his Lives of Eminent Persons, to have had the same story from Izaak Walton, who gave Dr. Morley again as his autho- rity ; and Aubrey repeats the tale with cer- tain additions, and notably with that of Dr. Pell's authority, at p. 577 of the same volume. The same story was pointed out to me by one of the officials in the Bodleian Library as being given in an anonymous biographical Miscellany to be found in the Rawlinsonian Collection, B 158, pp. 152-153. This MS. appears to be of the latter half of the seventeenth century, and its legend runs to the following effect. A certain Henry, Earl of Northumberland, being imprisoned in the Tower, did, for the better passing of his time, get several learned persons to live and converse with him ; one of these men (whom, Aubrey tells us, I. c. p. 368, the world called the Earl of Northumberland's magi) was ' Mr. Warrener.' And the MS. proceeds, ' He was the inventor, probably, of the cir- E 2 52 dilation of the blood, of which subject he made a treatise, consisting of two books, which he sent to Dr. Harvey, who epitomised and printed them in his own name ; he usually said that Dr. Harvey did not under- stand the motion of the heart, which was a perfect hydraulik Dr. Pain, that very ingenious and learned canon of Christ Church, told me that he had seen and perused this book of WarrenerV Finally, the excellent Biographia Britannica has em- balmed Wood's and Aubrey's story, in the articles 'Harriott' and 'Harvey,' pp. 2542 and 2550, ed. 1757. Many d priori impro- babilities will at once be seen to attach to this story, and it is easy enough to discredit more than one of the witnesses. But I have better than indirect evidence to bring for- ward, and I will have the agreeable mental exercise of excogitating it to the ingenuity of my hearers, which ingenuity will be sharp- ened, no doubt, by their regard for their own Harvey, and strengthened by the belief that ' Whatever records spring to light, He never shall be shamed.' I may be asked, after this quotation, why 53 I should have thought it worth while to in- vestigate Walter Warner's claims at all. I will shelter myself, in the first instance, behind the example of Sir George Ent, who, feeling and acting by Harvey as Launcelot in his better days felt and acted by Arthur, took similar pains to set aside the similar fable as to Harvey's indebtedness to Father Sarpi. And, in the second place, I will remind my hearers that it was but as recently as 1838 that an article appeared in the London and Westminster Review, in which the claims of the Italian monk just mentioned were once again brought forward with surprising con- fidence, plausibility, and ignorance. It was possible, I thought, that the same paltry but evil spirit which animated Dutens in writing his Inquiry into the Origin of the Discoveries attributed to the Moderns (1767 k), and in coming to the conclusion k Dutens was as well acquainted with the excellent work of William Wotton, Reflections upon Ancient and Modern Learning, published in 1694, on the other side of the question, as a little bitter mind can ever be with a work or the working of a noble and generous one. His repeated references to it show this, as also the unim- provable character of his shallow poverty-stricken spirit. 54 that every great man in modern times had been anticipated by somebody or other in ancient ones, might still be going about in dry places, and might wholly enter into and entirely fill up the soul of some small an- tiquary, who, coming under such inspiration and guidance upon the passages which I have collected, might proceed to instruct the literary public as to Warner's claims. Whilst considering what indirect evidence might be brought together to rebut this pos- sible attempt at detraction, I came upon what led me to the discovery of the direct evidence I have promised to lay before you, in the shape of a clue which brought me, after a somewhat tortuous course, upon Walter Warner's actual autograph MS. I found, whilst following up Dr. Pell's history, scattered through Dr. Birch's unindexed His- tory of the Royal Society, that Dr. Birch had procured a number of MSS. of Mr. Walter Warner's for that Society mixed up with Dr. Pell's (see vol. ii. p. 342 ; vol. iv. p. 447). Coupling this statement with the voucher for Warner's claims, ascribed by Wood and Aubrey to Dr. Pell (who, however, is never 55 reported in Dr. Birch's History, so far as I found, to have given currency to this state- ment), I thought that by these MSS. I should be able to test the truth of these statements. But the librarian of the Royal Society knew nothing of any MSS., either of Pell's or of Warners; and, as the result will show, it would have been odd if he had — at least, in his official capacity. I then made inquiry of the Duke of Northumberland, in whose library the MS. of Warner, once a pensioner of his house, might possibly be preserved ; but Mr. J. E. Martin informed me that this hope was a vain one. I found that Sion College had once possessed one MS. of War- ner's ; but I learnt from the Rev. W. W. Mil- man that they had lost it, and much besides, in the great fire of London in 1666. Finally, when taking the register of Merton College up to the British Museum for the purpose of comparing the entries made in that volume during Harvey's wardenship with his one authentic autograph MS. now in the national collection, I bethought me of making, at the same time, some inquiries as to Warner and Pell ; and at last, when I least expected it,

1. On the Diseases and Injuries of Arteries, with the Operations required for their Cure; being the substance of the Lectures delivered in the Theatre of the Royal College of Surgeons in the spring of mdcccxxix. By G. J. Guthrie, F.R.S. London, 1830.
2. The statement made (by Dr. Akenside; see Pettigrew, 'Medical Portrait Gallery,' Preface, p. 7, citing Dr. F. Hawkins) in the Praefatio to the College of Physicians' edition of Harvey's works to the effect that only two of Harvey's Letters had been published prior to the year 1766, is not correct. Horstius, as Harvey's words in the Epistola Sexta, p. 631 (Harveii Opera, ed. 1766) show, when read in connexion with the Epistola immediately
3. See also, I would add, Gregorius Horst, the father of Harvey's correspondent of the same name, in his Opera Medica, i. p. 83 (1661), where Riolanus is spoken of as 'anatomicorum hujus saeculi fere primum ;' and consult Bartholinus himself, who, in his work De Lacteis Dubia (1654), refers to 'multis Riolani observationibus quibus rem anatomicam immortali nominis celebritate auxit.'
4. I take this opportunity of expressing my surprise that Henle has not seen his way towards accepting this view of the real nature or Bedeutung of the Peyerian follicles. In his 'Gefasslehre' of 1868 (p. 404) he refers us back to his 'Eingeweidelehre,' p. 57, of 1862, where, as also in the second edition, 1873, p. 62, the absorbent character of these structures is denied, just as it was by Hyrtl in his 'Handbuch der Topographischen Anatomie,' 1860, p. 646, and by Teichman, 'Das Saugadersystem,' 1861, pp. 86-91. The view which I have adopted was accepted by a distinguished Fellow of this College, Dr. Burdon-Sanderson, in the Eleventh Report of the Medical Officer of the Privy Council for 1868, p. 96.