1

extrusion and the consequent sacrifice of the cell; (3) in the case of motor cells, a gradual recovery, at least for the time, to their original chromatic or or "pyknomorphic" condition was noted, while the sensory cells in great numbers disappeared absolutely. In illustration of these facts, Van Gehuchten gives carefully executed drawings. More recently, Goldscheider and Flatau 1 have studied changes induced in cells by various poisons of an organic and inorganic nature. Their results, with the use of tetanus toxin, are particularly interesting, as also are the effects they have observed to follow the exposure of animals to high temperatures. There appears to be a very noticeable enlargement of the cell nucleus in tetanus, and a complete chromatolysis seems to be induced by excessive temperatures. Interesting, however, as these researches are, we are not yet in a position, as these authors confess, to draw very certain conclusions from them.

This sketch of the changes, pathological and experimental, met with in the visceral innervation, shows how little is, as yet, positively known of the alterations which underlie neuro-visceral disorders; but it likewise declares plainly that the night is past, and that daylight, more or less clear, cannot be very long delayed. 1 "Norm. u. pathologische Anatomie der Nervenzellen,” Berlin, 1898.

LECTURE V.

IT

THE DISORDERS OF VISCERAL SENSIBILITY.

It may be remembered that, while discussing some points in the physiology of the visceral nervous system last year, I drew a parallel between viscero-motor actions in general and cardio-motor action in particular, arguing that, while the products of such motions differed with the organs which were the seat of motion, the mechanism of such action, whether anabolic or katabolic, was essentially the same. It is possible in Protean nature to push a parallel too far, and I have no desire to become too general in discussion. But it appears to me that it will be convenient, in considering the relation of the nervous system to disease and disorder in the viscera, to divide these into two large categories, namely, into disorders of sensibility or sensation, and into disorders of motility or motion.

The brain could no doubt be thus considered collectively with the other viscera, but there is a certain difference between the former and the latter which, together with the special character of this lectureship, renders it desirable that that viscus should receive separate treatment. The distinction consists in the fact. that, whereas the control of the viscera generally by the brain is through the agency of nerves, structures continuous with it, and inseparable from it, the influence exerted upon the brain by the rest of the body is not only by way of the sensory channels which come to it embryologically, although they leave it physiologically, but also by means of the blood which in great measure goes from it. There is indeed throughout the body, as there is in every organ, a functional unity, which might be more accurately termed a tri-unity, due to the consentaneous operation for the production of a common result of the peripheral organic cell, whether in brain or muscle, a central regulating cell and its nerve

channels, and the bond of union between the two, namely, the blood with its stimulating and life-giving properties.

Recent physiological thought appears rather to have dissociated this essential unity, and much ingenuity has been exerted to show how very well the organs can get on without the nervous system. The question of non-neural cardiac rhythmicality we touched upon last year, and traced the controversy from the now untenable assertion of an absence of nerves in general in the cardiac apex, to that of an absence of ganglion cells in particular in that portion of the organ.

Personally, I endorse Henry J. Berkley's physiological standpoint, although I cannot agree with his description of the cardiac ganglion. His words are "Cajal, in portraying the Auerbach plexus by the vital blue method, gives a picture that is not entirely dissimilar to our cardiac nerve-plexus with the neural enlargements and nerve-cells. Though in the cardiac plexus the nervecells are vastly inferior in number, different in appearance, and do not occur in clusters, yet the general likeness is sufficient to allow of some comparison being drawn between the two."1 This is fairly correct as regards the lower third of the heart which Berkley examined, and I shall show some of these ganglia of the apex which agree in great measure with this description. But in applying his words to cardiac ganglia generally, Berkley's description is not correct. As I demonstrated last year, the cardiac ganglia of the vagal system, as I take them to be, may consist of very large clusters of cells, such as the fine specimen which was figured in the Edinburgh Medical Journal last year (Figs. 11 and 12). My reason for regarding such ganglia as pertaining to the vagal system is, that they bear much the same relation to the peripheral distribution of the nerve that the plexiform ganglion does to it at its origin, and they are to be met with in many of the organs to which the vagus is distributed. The important point, however, is that, character apart, the apex of the heart, although not profusely, is nevertheless sufficiently ganglionated, and the Hallerist must look for some other support than his anatomical argument. Physiology affords more scope to the imagination. But we saw that the presence or absence of ganglionic cells was, after all, a matter of small moment to the Hallerist. They were nutrient or something else. In any case they had little to do with motion in any organ. You cut a vagus and the heart does not feel it long. You detach an organ and stimulate it, and the 1 Johns Hopkins Hosp. Rep., Baltimore, 1894, p. 89.

functional result is there. It has been shown, however, that if you cut both vagi the staying power of the heart is seriously compromised. Balint1 has shown that if aortic regurgitation be artificially established, and one vagus cut, the action of the heart is not materially interfered with; the compensated organ continues to act efficiently. But that if both vagi be divided, the heart, even although it has undergone compensatory hypertrophy, soon gives out, and the animal dies in about a week with well-marked evidences of retrograde stasis. I have already mentioned a case in which Billroth accidentally excised a portion of one vagus during an operation in the neck, with only temporary disturbance of the heart's action; and my colleague, Mr. Watson Cheyne, has recently mentioned to me another case not yet published, and which he has kindly permitted me to refer to on this occasion. During an operation for malignant disease involving the larynx, he found it necessary to excise a considerable portion of one vagus. The immediate consequence of this appeared to be an arrhythmical action of the heart which subsided in a few days; but the stability of the organ has apparently been more permanently impaired, because slight emotional excitement re-induces the condition, which was not present prior to the operation. Survival after the division of one nerve is probably the result of what may be termed incomplete peripheral decussation in the organic plexus, a subject, as it appears to me, of much practical interest, and one which I have examined somewhat, but my results are still too rudimentary for publication. The nerve from one side probably sends fibres to both sides in such unified organs as the heart, while division of both nerves naturally destroys such a nerve supply and saps the fountains of persistent rhythmicality.

Inasmuch, however, as anatomy lies at the foundation of our knowledge of all forms of organic activity, it would have been a difficult matter for the adherents of a neural theory of sustained motion to have defended their position, had it been possible to point indubitably to mobile structures which continued efficiently to act for a lifetime without such endowment. The conception of such a condition would a priori seem unreasonable, but as the unexpected does occasionally happen, it was just possible that such a fact might conveniently come to the aid of the distressed Hallerist. This was supposed to be so in the case of the intracranial vessels. Some of the peculiarities of the intracranial circulation certainly appear, at first sight, to lend probability to 1 Deutsche med. Wchnschr., Leipzig, 1898, Nos. 1 and 2.

the occurrence of an exceptional condition in this sphere. The resistant skull-cap, Alexander Monro the second's suggestion of the full bottle held upside down without spilling its contents, Kellie's well-known experiments, and much argument founded thereon, suggested that vasomotor nerves had little to do with the intracranial circulation. Some, like Hill and Bayliss,1 argued that nerves were absent because they had not been found, and for the purposes of their theory it was necessary to assume such absence.

In my ignorance I had assumed that these vessels were innervated, until Sir John Tuke informed me last year that they were supposed not to be. Were this so, I felt that I was standing upon somewhat thin ice in much that I had to say, and found it advisable to proceed somewhat a-tiptoe until I felt more secure, although I suppose walking a-tiptoe does not materially lessen your weight, but it may avoid the clumsy kick which would bring about a sudden and ridiculous immersion. I therefore determined to investigate the point at an early stage of animal life, when the tissues appear to be, as a rule, most amenable to staining methods. As I have related in the Edinburgh Medical Journal for November 1898, I selected the fully-grown fœtus of a cat for the purpose, and was fortunate enough to find not only that the pial vessels were fully innervated by an ample plexus, but also that branches of nerve might be found in close relation to blood vessels which bore fully developed and permanent ganglion cells.2

As I owed it to Sir John Tuke that I had undertaken the research at all, I considered it my duty to inform him first of the result, which I did while he was at Aix-les-Bains last June. I have since discovered that Obersteiner found some such nerves on an old-gold preparation in 1897, and understand that Dr. Gulland also found the intracranial vessels to be innervated in July 1898.

Thus, then, another non-neural persistent rhythmicality has found its way to the limbo of many an ingenious hypothesis. The preparations under the microscope show these structures, the relation of which to sleep and cerebral activity must be a very important one.

Assuming, therefore, that the nervous system bears an important relation to splanchnic as well as somatic motion in health, I assume also that that relation is quite as important in the case of disordered visceral sensibility and motion.

Having argued that motion, whether sensory or mobile, to use 1 Journ. Physiol., Cambridge and London, 1895. 2 Appendix, p. 124.