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A most interesting symposium on the staining of nervefibres and cells occupied the greater part of Thursday’ssession, new and valuable methods being announced byDr. GEORGINE LUDEN VAN HEUMEN (Munich), Dr. C. A. U.KAPPERS (Amsterdam), and Dr. RENE SAND (Brussels).

Professor ADOLPH MEYER (Johns Hopkins University)showed three beautiful glass reconstruction models of thehuman brain.

Professor WAHLBY (Cairo, Egypt) demonstrated very fullyhis methods of corrosion by which the finest ramifications ofthe body cavities and the vascular system can be demon-strated.

Other papers presented were relative to exhibits in thesection of Museum Technique of the Congress Museum byDr. E. C. ROSENOW (Chicago), representing the pathologyand etiology of endocarditis, Professor DELEPINE (Man-chester), illustrating various types of infectious diseases, andDr. A. A. BRUERE (Montreal), showing mounted colonies offungi in gelatine plate cultures sealed with paraffin.

THE SECTIONS.SECTIONS I. AND III.—JOINT SESSION OF THE SECTIONOF ANATOMY AND EMBRYOLOGY WITH THESECTION OF GENERAL PATHOLOGY AND

PATHOLOGICAL ANATOMY.

THURSDAY, AUGUST 7TH.President, Professor ARTHUR THOMSON.

Discussion on the Excitatory and Connecting MuscularSystem of the Heart.

The PRESIDENT of Section 1. (Anatomy and Embryology),Professor ARTHUR THOMSON (Oxford), introduced the

reporters to the meeting, and in his opening address welcomedthe members of the two sections which were to take part inthe discussion.

Dr. Ivy MACKENZIE (Glasgow) gave an abstract of his

report which dealt with the Comparative Anatomy of theExcitatory and Connecting Muscular System of the Heart.He pointed out how variable was the development of thissystem not only in different classes but even in different

species ; and he traced the evolution of the undifferentiatedheart tissue from the simple condition in the fish to thescattered and complicated condition in the mammal. Thisevolution took place hand in hand, and was indeed causedby the growing complexity of the heart chambers in the

higher orders. Dr. Mackenzie pointed out, however, that nomatter how this tissue was disposed in the heart wall and towhatever degree its scattering and complexity was carried, italways retained its own distinctive features, among whichwas its abundant nerve-supply, which differentiated it fromheart muscle fibres to which nerve terminations were difficultor impossible to trace.

Dr. 0. JosuE (Paris) gave an abstract of his report onLes Localisations Cardiaques. The speaker directed particularattention to the clinical aspect of the question, and demon-strated that clinical experience dictated the belief that theheart mass was composed of different kinds of musculaturewith different physiological roles to discharge. Pathologicallesions made this clear. Lesions of the myocardium, evenwhen very small, were capable of producing profound clinicalmanifestations, whilst on the other hand extensive lesions

might produce very little disturbance. The localisation ofcardiac myocardial lesions determined the clinical symptoms.

Dr. THOMAS LEWIS (London) demonstrated his report onthe Pacemaker of the Mammalian Heart. This demonstra-tion was for the most part concerned with an explanation ofthe methods of research. In the simple non-mammalianheart the anatomical conditions rendered research more easy,for with the electrocardiogram the actual progress of theprocess of contraction may be studied. Experiments weredetailed which showed that by an artificial excitation a

cardiographic tracing could be produced similar to that

given by a normal beat. This occurred only when oneparticular point was chosen for excitation, and this pointcorresponded anatomically with the site of the sinu-auricularnode. Dr. Lewis then detailed experiments dealing withdamage or excision of the node or of the a. -v. bundle, showingthat the difference of method accounted for the differentresults obtained by various investigators.

Professor KULBS (Berlin) then read his report on theAnatomy of the Bundles of the Heart. This report dealt

i exhaustively with the condition found in the hearts ofi different zoological types. In the fish with one auricle and.

one ventricle a simple "funnel" transmits the musculatureof the auricle to the ventricle. In amphibia and reptiles withtwo auricles and one ventricle the funnel" becomes divided.

I into two parts. In birds with two auricles and two ventriclestwo separate funnels" exist, joined only at the inter-ventricular septum. In mammals the complete system.consists of (1) the Aschoff-Tawara node, (2) the bundle ofHis, and (3) the extension from this which runs beneaththe enducardium of both ventricles. In fish, amphibia, andreptiles the differentiation of this system from heart muscleis by no means so complete as it is in birds and mammals.

Dr. A. F. STANLEY KENT (Bristol), in giving the first

independent paper, laid stress on the need to study moreattentively the possibility of other connexions betweenauricle and ventricle than that furnished by the a.-v. bundleitself. Clinical cases and actual anatomical investigationshowed that other connexions existed, and that neuro-

muscular elements were present which could function at.times independently of the main bundle.

Dr. Louis FAUGERES BISHOP (New York) spoke in favour-of recognising functional disorders of the structures of theheart altogether apart from anatomic changes. Toxicardia,possibly due to particular protein derivatives to which theheart has become sensitive, accounted for nine-tenths of thecases met with clinically. Treatment demonstrated thecorrectness of these views. No doubt these toxicardia cases,.which had a purely functional initial stage, proceeded to-anatomic changes ; but it was essential for the clinician tOo

recognise that there rvas a primary functional stage.Professor ARTHUR KEITH (London) entered a plea for

further study of the function of the bundle, for he con-sidered it by no means certain that conductivity alone was.the role of this structure. He advised research beingdirected towards other organs, such as the stomach, wherethere was evidence of similar connexions and mechanisms.in the musculature. ’

Dr. ALEXANDER MORISON (London) made reference to the-disposition of the nodal tissue in a malformed heart ofwhich he had made an exhaustive study.

Dr. C. E. LEA (Manchester) and later, Professor K. F.WENCKEBACH (Strassburg) produced clinical evidence that.the bundle was no mere connecting bond, that other func-tions were in all probability lodged in it, and that thecondition of the ventricle to respond to a transmittedstimulation had to be reckoned with.

Professor L. MUSKENS (Amsterdam) and Dr. A. D.HIRSCHFELDER (Baltimore) dwelt especially upon experi-ments carried out on the heart of frogs. Professor P. L.ASCHOFF (Freiburg) and Professor A. D. WALLER (London),having spoken, the reporters replied.

SECTION III.-GENERAL PATHOLOGY AND PATHO-LOGICAL ANATOMY.

WEDNESDAY, AUGUST 6TH.

President, Professor S. G. SHATTOCK (London).The PRESIDENT opened the proceedings by welcoming the

members of the section, and then in a short introductoryaddress said that one thing all must have long since dis-covered from personal experience was the large proportion,of work which was unattended with any positive result.The tentative questions which when put to the test of £

experiment received negative answers would, if added up,far outnumber the contrary. How much brilliant andpromising work had they not all designed, the results ofwhich had never been recorded because they had falleninto the barren category. In a certain sense they could notbe dissatisfied with such negations, since something that was.deemed possible had been disproved, and the way cleared,in the same degree, to the access of positive truth. Human

biology was unique in that every form of energy in theuniverse was concerned and took part in the final phenomenon,of life. The explanation of what one might call this

"negative science " (from the I discoveries " in which noteven the greatest were exempt) was, of course, the incalcu-lable complexity of what was investigated, as contrasted withthe limitations of the researching instrument--the investi-gator. One ever-present temptation arising from such astate of things, and one to which they all in some degree