86German anatomists divide this axis into trunk and crown (HirnstammandHirnmantel). There is convenience in this division. If we remove all the gray matter of the cerebrum, with all the white matter radiating from it, until we again come upon gray matter—and if we then cut the cerebellum from its descending strands of white matter—we shall have removed thecrown, and leave thetrunkremaining. This trunk is constituted by the corpora striata, nucleus lentiformis, optic thalami, corpora quadrigemina, crura cerebri, pons, medulla oblongata, and medulla spinalis. From this trunk all the organs of the body are directly innervated (except those innervated from the sympathetic?).87“On s’est préoccupé du rôle spécial que pouvaient jouer les ganglions périphériques situés dans le voisinage de certaines organes; et on a prétendu que les nerfs ne jouissaient de leur propriété d’agir sur ces organes qu’après avoir traversé ces ganglions. On avait admis que l’excitation portée sur le filet nerveux avant son entré dans le ganglion restait sans effet; que pour obtenir l’action excitatrice des fonctions de l’organe il fallait exciter le nerf entre lui et le ganglion voisin.”—Claude Bernard,Systéme Nerveux, II. 169. But on proceeding to verify these statements by experiment,Bernardis led to the conclusion, “que le ganglion n’a pas d’influence propre sur le mode de l’excitation transmise à l’organe.”I was delighted to find my opposition to the current teaching respecting the central functions of ganglionic cells thoroughly borne out by the elaborate researches ofSigmund Mayer(Archiv für Psychiatrie, Bd. VI. Heft 2). Having artificially produced such cells, he pertinently asks, How can we attribute central functions to cells which appear in the process of regeneration of a divided nerve! The error has its origin in the confusion of functions with properties.88It is often, though incorrectly, stated that every segment of an annulose animal has its separate ganglion. The fact is, that while the ganglia are usually fewer than the segments, they are sometimes more numerous.89It has been proved that the cells of the cornea and the pigment cells of the skin contract under nervous excitation. We cannot suppose that although these are the only cells which have hitherto been brought under experimental observation, they are the only cells subject to nerve-influence. We may safely assume that wherever a nerve-fibre terminates, its action will be transformed into an excitation of the part. Habitually, however, motor-nerves are spoken of as muscle-nerves.90On Deduction, seeProblems: First Series, Vol. II. p. 15991I do not here touch upon the question as to whether these actions of the senses aresensations, because that question demands that we should first settle what isSensation. I may at once, however, say that what is ordinarily understood as a sensation ofcolor, or a sensation ofsound, is, in my opinion, not possible without the cerebrum. But the sensibility of the eye and ear is manifestly preserved.92It has been observed that removal of the cerebellum affects the pigment cells of the skin. No doubt other parts are also affected, but the changes have hitherto escaped observation.93Owsjannikowdescribes the results of removing carefully the cranial ganglia of the crayfish; and these effectsMeyerobserves to be identical with those which follow removal of the large claw of the crayfish!A. B. Meyer,Das Hemmungsnerven-system des Herzens, 1869, p. 23. Let me add that the phenomena described by M.Faivreas following the destruction of one subœsophageal ganglion in theDytiscus, are so little to be referred to the mere absence of the ganglion, that I find them not to occur when the whole head is removed.94Pflüger,Die Sensorischen Funktionen des Rückenmarks,1858.Auerbach,Günzburg’s Zeitschrift. Jahrgang IV. p. 486.Lewes,Leeds Meeting of British Association, 1858, andPhysiology of Common Life, 1860.This recognition of sensation, and even of volition, in spinal actions may be found in the writings ofWhytt,Unzer,Prochaska,Legallois, andMayo; but the establishment of the Reflex Theory had displaced it, and its revival dates fromPflüger.95Friedländer(Versuch über die innern Sinne, 1826, I. 77) declares it to be a rational necessity: “Die Annahme eines Nervenfluidums ist Nothwendigkeit der Vernunft.”96These terms and the conception they embody were proposed by me in 1859 in a paper “On the necessity of a reform in Nerve-physiology,” read at the Aberdeen meeting of the British Association, and were reproduced in thePhysiology of Common Life. (Prof.Owen, probably in forgetfulness of my suggestion, proposed “neuricity.”Lectures on the Comp. Anat. of Vertebrates, 1866, I. p. 318.) The terms were fortunate enough to meet with acceptance from some physiologists both in England and France; and the conception has been more widely accepted than the terms. The most distinguished approver was Prof.Vulpian. “Faute d’une meilleure détermination on peut, avec M. Lewes, donner à la propriété physiologique des fibres nerveuses le nom deneurilité; c’est là ce qui correspondra à la oontractilitè des fibres musculaires.”Leçons sur la physiologie du système nerveux, 1866, p. 220. He also adopted my suggestion (since modified) of Sensibility as the property of ganglionic cells. Compare alsoGavarret,Phénomènes physiques de la Vie, 1869, pp. 213 and 222.Taule,Notions sur la nature de la matière organisée, 1866, p. 131.Charles Robin,Anatomie et physiologie cellulaires, 1873, p. 166.By these channels, and by the German, Italian, Russian, Polish, and Hungarian translations of my work, the suggestions were carried over Europe, crept into scientific journals, and became known to writers who never heard of me. I only mention these facts lest the reader should suppose that my views had been anticipated by certain continental writers.97“La force nerveuse n’existe pas comme puissance independant des propriétés de tissu. Elle consiste en l’action des parties excités, sur les parties excitables, l’état de l’excitation des premières agissant comme impression ou stimulation sur les secondes.”—Landry,Traité des Paralysies, 1859, I. 142.98“Le système nerveux est tout à la fois l’origine des sensations et l’origine des mouvements. Mais est-ce par une propriété unique, ou par deux propriétés diverses qu’il détermine deux phénomènes aussi distincts!”Flourens,Recherches sur les propriétés et les fonctions du Système Nerveux, 1824, p. 1. He concludes that “la puissance nerveuse n’est pas unique; il n’y a pas une seule propriété, il y en a deux,” p. 24. In this he has been generally followed.99“I have raised and stretched the thick orbital nerve of horses on the handle of a scalpel, like a string on the bridge of a violin, without exciting the least sensation; but as soon as mechanical or chemical irritation had given rise to inflammation of the nerve a gentle touch caused violent pain.”—Romberg,Nervous Diseases(translated for the Sydenham Society), I. 10.100The experiments ofHaller,Sur la nature sensible et irritable des parties, I. 245; and the remarks ofProchaska,De Functionibus Systematis Nervosi(translated byLaycockin the volume published by theSydenham Society, p. 396), ought to have sufficed. See further on,Chap. V.101In mammals about three days, in birds four days, in frogs fourteen to twenty days.102Rutherford, inJournal of Anatomy, 1873, No. VIII. p. 331. (Fleischldenies that the nervein situhas different degrees of reaction.Sitzungsberichte der Wiener Akad., December, 1876.)103Munk, in theArchiv für Anat., 1860, p. 798.104Haller,Mémoires sur la nature sensible et irritable des parties.105Comptes Rendus, 1862, LIV. p. 965.106“J’espère vous convaincre que tous les éléments anatomiques des nerfs sensitifs, moteurs, vasomoteurs, et autres, ont les mêmes propriétés, et ne sont distincts que par leurs fonctions. Cette question est de la plus haute importance pour la physiologie générale. C’est celle qui domine toute la physiologie des fibres nerveuses.”—Vulpian,Leçons sur la Physiologie du Système Nerveux, p. 11.107Mr.James Andrews.108In the second number ofLa Revue Philosophique, Paris, 1876, I have treated this question of specific energies more at length than I could find space for in the present volume.109In 1859 I mentioned that if the nerves of a frog’s back be exposed by raising the skin, they may be pricked or even cut without sensible effect, although a slight prick on the skin will excite the nerves, and cause a reflex action. In 1870, Prof.Fickexpressed his astonishment at finding that after he had cut out a piece of the skin, leaving it attached to the body by a single nerve, electrical stimulation of this excised skin caused the frog to make the reflex movement of rubbing the irritated surface; whereas electrical stimulation of the nerve-trunk itself produced no reflex effect, only a twitching of a muscle.Pflüger’s Archiv, 1870, p. 327.Brown Séquardtries to establish a distinct species of nerves asconductorsof sensitive impressions, from those which areimpressionable. The facts on which he founds these two properties simply show that nerves are so disposed that the stimulus which excites them in one place fails in another. He could hardly maintain that a skin nerve contained impressionable fibres at its periphery, and only conducting fibres in its trunk! See his communication to the Royal Society,Proceedings, 1856; andLecturesin theLancet, 10th July, 1858.110In consequence of this observation some physiologists have maintained that Feeling or Consciousness never arises in cerebral activity, unless the thalami and the connected tracts are at the same time in action. I go further, and maintain that there is no Consciousness (in the restricted meaning of the term)unless the whole organism is involved. Cerebral or spinal activity will be activity of Sensibility; but this is only the basis of Consciousness.111“An unconscious sensation, which Lewes distinguishes from perception, is to me an inconceivable (ist für mich ein Unding).”—Schröder van der Kolk,Die Pathologie des Geistes-Krankheiten, p. 22.112By selective adaptation is meant the varying combination of motor impulses to suit the varying requirements of the effect to be produced. Physical mechanisms are limited to the performance of definite actions; sensitive mechanisms employ fluctuating combinations of elements in response to fluctuations of stimuli. The wheels, levers, springs, and valves of a machine cannot be differently combined according to varying degrees of the motor-force, as the nerves and muscles of an organism are differently combined by varying sensations. An automaton may be constructed to play on the violin, but it will only play the air to which it isset; it cannot vary the performance,—cannot play a false note, or throw in acrescendohere, alargothere, according to a caprice of feeling. We must admit that violinist has his delicate and changing movements guided by sensations, auditory and muscular; any interruption in the sensations would arrest the movements, which in truthincorporatethem. And yet it is well known that the violinist may perform while completely “unconscious.” I do not simply refer to the fact that his thoughts and attention may be elsewhere; I refer to such facts as are recorded in Pathology.Trousseau, for example, had an epileptic patient who was occasionally seized with attacks of complete unconsciousness while he was performing in the orchestra; yet, on reawakening to consciousness, he found that he had continued to play, had kept proper time, and played the proper notes.113Claude Bernard,Système Nerveux, 1858, I. 349.114Wordsworth,The Prelude.115“On peut dire que toujours un phénomène de mouvement reconnait pour point de départ une impression sensitive.”—Claude Bernard, I. 267.116Since this was written Prof.Michael Fosterand Mr.Dew Smithhave published their very important researches on the motions of the heart, which establish beyond a doubt that, in the molluscs at least, there is no co-operation of either centre or nerve.—Proceedings of the Royal Society, 18th March, 1875. (See also Studies from the Physiological Laboratory of Cambridge, Part II., 1876.) Mr. Foster knows that I had independently, and from a totally different line of research, arrived at the same conclusion respecting the heart’s movement.117Comptes Rendus de la Socíété de Biologie, 1847, I. 40. In 1856 he showed that not only were the muscles of the iris directly stimulated by light (and this not by its calorific or chemical rays), but that sixteen days after removal of the eye from the orbit, this effect was observable in the eel. Yet a very few days after extirpation of the eye the nerves are disintegrated.—Proceedings of the Royal Society, 1856, p. 234.Dondershas the following observations: “The movements of the iris are of two kinds—reflex and voluntary. Reflex action is exhibited as constriction of the pupil in consequence of the stimulus of incident light upon the retina. Fontana has shown that the light falling upon the iris produces no remarkable contraction. We have confirmed this result by causing the image of a small distant light to fall, by means of a convex lens, upon the iris, whereby, during slight perception of light, a doubtful contraction occurred, which gave way to a strong contraction so soon as the light entering the pupil excited a vivid perception. Nevertheless, the experiments of Harless and Budge have shown that even after death, so long as irritability remains, the pupil still contracts upon the continued action of light. Of the correctness of this we have satisfied ourselves. In a dog killed by loss of blood the one eye was closed, the other opened and turned to the light: after the lapse of an hour, the pupil of the opened eye was perceptibly smaller than that of the closed eye. The latter now remained also exposed to the light, and on the following day the diameter of both eyes was equal. The upper jaw, alone with the eyes, was taken out of some frogs; one eye was exposed to the light, while the other was covered with a closely folded piece of black paper: after the lapse of half an hour the pupil turned to the light was narrow, the other wide. But the latter also contracted almost immediately after the removal of the paper.”—Donders,On the Anomalies of Accommodation and Refraction of the Eye. Trans. of the New Sydenham Society, p. 572.118The experiment often fails, but I have seen it several times succeed.119Pflüger’s Archiv, 1872, p. 618.120See his Researches inPflüger’s Archiv, Bde.II. and IV.121D’Orbigny,Des Mollusques Vívants et fossils, p. 113.122Seaside Studies, 2d ed., p. 101.123Cited byBrown Séquard,Journal de la Physiologie, 1858, p. 359.124Dr.Norrishas recorded some striking observations in his paper on “Muscular Irritability” in theJournal of Anatomy, 1867, No. II. p. 217. Here is the only one I can find room for: “On taking up thedeadfrog and touching the limb (which during life had been paralysed by section of its nerve) with my finger,it was suddenly shot out as if alive. I placed the body down, and one or twoapparently spontaneous movementsof small extent afterwards occurred. On touching the skin gently with the point of a needle, by the slight pressure upon the muscle beneath, movements of the limb were also induced, but this high degree of exaltation very rapidly disappeared.”125See their papers in theArchiv für Psychiatrie, 1875, Bd. V. Heft 3.126This latter statement will be justified when I come to expound the Triple Process, which I have named thePsychological Spectrum.127FosterandBalfour,Elements of Embryology, 1874, Part I. p. 52.His,Untersuchungen über die erste Anlage des Wirbelthierleibes, 1868, p. 197.128They state that the cells of the epiblast are the results of direct segmentation, whereas the cells of the other layers are formed at a subsequent period, and are only indirectly results of segmentation. But if the observations ofKowalewskyare exact, this is not the case with the hypoblast of the Amphioxus, which is from the first identical with the epiblast.129Kölliker,Entwicklungsgeschichte des Menschen und der höheren Thiere, 1861, p. 71.130[According toBalfour’srecent observations, a large part of the muscular tissue is derived from the layer of the mesoblast belonging to the hypoblast.]131His,Untersuchungen, pp. 39, 40.132Quite recentlyOwsjannikowhas pointed out the termination of fibres in the phosphorescent cells of theLampyris Noctiluca. See his paper in theMémoires de l’Acad. de St. Petersbourg, 1868, XI. 17. These phosphorescent cells are said to be ganglion-cells byPanceri,Intorno della luce che emana dalle celleule nervose(Rendiconto della Accad. delle Scienze, April, 1872); and byEimer,Archiv für mikros. Anatomie, 1872, p. 653.Köllikeralso calls the phosphorescent organ a nervous organ. This is not to be interpreted as meaning that neurility is phosphorescence, but simply that in some nerve-cells there is phosphorescent matter, which is called into activity by stimulus of the nerves.133BidderundKupffer,Textur des Rückenmarks, 1857, p. 108. [What is said in the text has been rendered doubtful by the recent researches of Mr.F. Balfour,On the Development of the Spinal Nerves in Elasmobranch Fishes(Philos. Trans., Vol. CLXVI. Part I.), which show that in these fishes the ganglion has its origin in the spinal cord.]134Comp.Problem I.§130, with the remarks ofCharles Robin,Anatomie et Physiologie Cellulaires, 1873, p. 20.135Kleinenberg,Hydra; Eine Anatomisch-Entwickelungs-Untersuchung, 1872, p. 11.Eimer,Zoologische Studien auf Capri, 1873, p. 66.A similar formation is described by Dr.Allmanin theMyriothela; he says, however, that he has never been able to trace a direct continuity of the caudal processes of the cells with muscular fibrils. He believes that the processes make their way to the muscular layer through undifferentiated protoplasm.—Philos. Transactions, Vol. CLXV. Part II. p. 554.An intermediate stage between this neuro-muscular tissue and the two differentiated tissues seems presented in the Nematoid worms which have muscles that send off processes into which the nerves pass.Gegenbaurdeclares his inability to decide whether these processes are muscles or nerves.Bütschlithinks the nerve-process blends with the muscle-process.—Archiv für mikros. Anatomie, 1873, p. 89.136“The gray matter of the cord seems undoubtedly to be formed by a metamorphosis of the external cells of the epiblast of the neural tube, and is directly continuous with the epithelium; there being no strong line of demarcation between them.”—Op. cit., p. 185.137Robin,Anat. et Physiol. Cellulaires, p. 332.138Stilling,Bau der Nervenprimitiv-Fasern, 1856, p. 16.139“There was a time,” saysKölliker, “when I confidently believed that an hypothetical explanation of the arrangement of elements in the spinal cord could be grounded on a basis of fact; but the deeper my insight into the minute anatomy, the less my confidence became; and now I am persuaded that the time is not yet come to frame such an hypothesis.”—Gewebelehre, 5te Auf. 1867.140In the Gasteropoda the cells range from 220 μ to 3 μ (μ = 0,001 millimètre).141Haeckel,Müller’s Archiv, 1857.Leydig,Vom Bau des thierischen Körpers, 1864, I. 84.Robin,Anat. et Physiol. Cellulaires, p. 89. Should the observations ofHeitzmannbe confirmed, there would be ground for believing that neurine is normally fibrillated. He says that the living protoplasm in the Amœba, white blood-corpuscle, etc., is an excessively fine network, which condenses into granules at each contraction. (Cited in theJahresberichte über Anat. und Physiol., 1873, Bd. II.)Walther, who examined frozen brains, describes the cells as quite transparent at first, with very rare granules, but gradually while under observation the granules became more numerous.Centralblatt, 1868, p. 459. According toMauthner,Beiträge zur Kenntniss der morphologischen Elemente des Nervensystems, 1862, p. 41, neurine has three cardinal forms—transparent, finely granular, and coarsely granular.142Trinchese,Struttura del sistema nervoso dei Cefalopodi, Florence, 1868, p. 7.143An eminent friend of mine was one day insisting to me that the physiological postulate made itimpossiblefor a nerve-cell to be without its ingoing and outgoing fibres; and he was not a little astounded when I replied, “Come into my workroom and I will show you a thousand.”144EichhorstinVirchow’s Archiv, 1875, LXIV. p. 432.145Auerbach(Ueber einen Plexus Myentericus, 1862) describes the ganglia as filled with apolar cells, among which only a few are unipolar.Stieda(Centralnervensystem der Vögel, 1868) finds both apolar and unipolar cells in the spinal ganglia of birds.Axmann(De Gangliorum Systematis Structura penitiori, 1847) says the spinal cells are all unipolar.Schwalbe(Archiv für mikros. Anat., 1868) andCourvoisier(ibid., 1869) say the same. So alsoRanvier,Comptes Rendus, 1875.Kölliker(Gewebelehre) speaks decidedly in favor of both apolar and unipolar cells, but thinks the apolar are embryonic.Pagliani(Saggio sullo Stato attuale delle Cognizioni della Fisiologia intorno al Sistema nervoso, 1873), who represents the views ofMoleschott, admits the existence of apolar and unipolar cells. The authors just cited are those I happen to have before me during the rewriting of this chapter, and the list might easily be extended if needful.Auerbach,Bidder, andSchweigger-Seideldescribe unipolar cells which in some places present the aspect of bipolar cells simply because two cells lie together, their single poles having opposite directions. I will add that the bipolar cells do not really render the physiological interpretation a whit more easy than the unipolar, for they are simply cells which form enlargements in the course of the nerve-fibres.146When Dr.Bealesays “that it is probable no nerve-cell exists which has onlyone single fibreconnected with it” (Bioplasm, p. 186), he has no doubt this in his mind; since he would not, I presume, deny that there are cells each with a singleprocess.147Deiters,Untersuchungen über Gehirn und Rückenmark, 1865.148Archiv für mikros. Anat., 1869, p. 217. Compere alsoButzke,Archiv für Psychiatrie, 1872, p. 584.149Henle,Nervenlehre, 1871, p. 58, Fig. 21.150When men of such experience and skill asKölliker,Bidder,Goll, andLockhart Clarkedeclare that they have never seen a cell-process pass directly into a dark-bordered fibre in the anterior root, what are we to say to such figures and descriptions as those given in the works ofSchröder van der Kolk,Gratiolet, andLuys? Even did such arrangements exist, no transverse nor longitudinal section could display them, owing to the different planes at which the fibres enter, and the length and irregularity of their course.151Long after the text was written,Willigkpublished inVirchow’s Archiv, 1875, LXIV. p. 163, observations of anastomoses which evenKöllikeradmitted to be undeniable. Yet out of sixty-four preparations, amid hundreds of cells, he could only reckon seven cases of conjunction.152See the history given inStilling’slearned work,Ueber den Bau der Nervenprimitiv-Faser, p. 34; and compareMax Shultze,De Retinæ Structura, p. 8, andBau der Nasenschleimhaut, p. 66;Waldeyer, in theZeitschrift für rat. Med., 1863;ListerandTurner,Observations on the Structure of Nerve-Fibres, inQuarterly Micros. Journal, 1859;Ranvier, in theArchives de Physiologie, 1872.153Virchow’s Archiv, Bd. LXXII. p. 193.154Monthly Journal of Micros. Science, 1874, XI. p. 214.155Babuchin,Centralblatt, 1868, p. 756.156Even so eminent an authority asW. Krauseholds this both with regard to the varicose aspect and the double contour:Handbuch der menschlichen Anatomie, 1876, I. 367.Butschli, however, describes the nerves in a living Nematode as varicose:Archiv für Anat., 1873, p. 78; and I have somewhere met with an observation of the double contour being visible in the living animal.157Butzke,Archiv für Psychiatrie, 1872, p. 594, states that the granular substance has the chemical composition of myeline. If this be so, we may suppose the “fibrils of crystallization” to represent the coagulation of the substance which is in solution amid the myeline granules, and corresponds with the axis cylinder of a fibre. I may remark that in almost every good preparation nerve-cells will be found in which, while one process is distinctly granular, another is striated or even fibrillated.158Boll,Die Histiologie und Histiogenese der nervösen Centralorgane, in theArchiv für Psychiatrie, 1873, p. 47.159Stieda,Studien über das Centralnervensystem der Vögel, 1868, p. 65.Mauthner,Op. cit., p. 4.160TurnerandLister,Op. cit., p. 8.161Blessig,De Retinæ Structura, 1857.162Luys,Recherches sur le Système nerveux, 1865, p. 267. In a recent and remarkable treatise the student is informed that “plus une cellule est chargée d’un rôle purement mécanique plus elle est volumineuse; plus l’acte qu’elle produit tend à revêtir un caractère psychique plus elle est petite”; to move a limb theagitationof the cerebral cells mustmaterialize itselfmore and more, “Il a besoin de passer par des cellules, de moins en moins spirituelles et de plus en plus matérielles.... De même pour les cellules sensitives. L’impression extérieure va en se modifiant, en se spiritualisant, de la périphérie au centre.... Un phénomène de l’ordre spirituel ne sanrait devenir sans transition un phénomène d’ordre physique.” And what is this marvellous transition between spiritual and physical? It is the action of medium-sized cells which “travaillent la vibration reçue, la modifient de façon à lui ôter de son spiritualisme et à la rapprocher davantage des ébranlements physiques.” I will not name the estimable author, because he is simply restating what many others implicitly or explicitly teach; but I will only ask the reader to try and realize in thought the process thus described.163Schröder Van Der Kolk,Pathologie der Geisteskrankheiten, 1863, p. 69.164Wundt,Physiologische Psychologie, p. 261. In hisMechanik der Nerven, 2 Abth.(published just as this sheet is going to press), he shows that a stimulus is both retarded and weakened in its passage through a ganglion.165Trinchesealso says that the fibres “provengono dalle cellule enon son altro che i loro prolungamenti o poli.”—Op. cit., p. 13. An unequivocal example is seen in theTorpedo, where the large cells have each their prolongation continuing without interruption into the electrical organ. See the figure given byReichenheimin theArchiv für Anat., 1873, Heft VI.166Golgi,Sulla struttura della sostanza grizia del Cervello.Arndt,Archiv für mikros. Anat.1870, p. 176.Rindfleischalso traces these processes into the neuroglia (ibid., 1872, p. 453). “Deiters, Boddaert, and other observers have stated that one dark-bordered nerve-fibre enters each cell.... My own observations lead me to conclude thatallthe fibres are composed of the same material, but that one fibre does not divide until it has passed some distance from the cell, while others give off branches much closer to it.”—Beale,Bioplasm, p. 189.
86German anatomists divide this axis into trunk and crown (HirnstammandHirnmantel). There is convenience in this division. If we remove all the gray matter of the cerebrum, with all the white matter radiating from it, until we again come upon gray matter—and if we then cut the cerebellum from its descending strands of white matter—we shall have removed thecrown, and leave thetrunkremaining. This trunk is constituted by the corpora striata, nucleus lentiformis, optic thalami, corpora quadrigemina, crura cerebri, pons, medulla oblongata, and medulla spinalis. From this trunk all the organs of the body are directly innervated (except those innervated from the sympathetic?).87“On s’est préoccupé du rôle spécial que pouvaient jouer les ganglions périphériques situés dans le voisinage de certaines organes; et on a prétendu que les nerfs ne jouissaient de leur propriété d’agir sur ces organes qu’après avoir traversé ces ganglions. On avait admis que l’excitation portée sur le filet nerveux avant son entré dans le ganglion restait sans effet; que pour obtenir l’action excitatrice des fonctions de l’organe il fallait exciter le nerf entre lui et le ganglion voisin.”—Claude Bernard,Systéme Nerveux, II. 169. But on proceeding to verify these statements by experiment,Bernardis led to the conclusion, “que le ganglion n’a pas d’influence propre sur le mode de l’excitation transmise à l’organe.”I was delighted to find my opposition to the current teaching respecting the central functions of ganglionic cells thoroughly borne out by the elaborate researches ofSigmund Mayer(Archiv für Psychiatrie, Bd. VI. Heft 2). Having artificially produced such cells, he pertinently asks, How can we attribute central functions to cells which appear in the process of regeneration of a divided nerve! The error has its origin in the confusion of functions with properties.88It is often, though incorrectly, stated that every segment of an annulose animal has its separate ganglion. The fact is, that while the ganglia are usually fewer than the segments, they are sometimes more numerous.89It has been proved that the cells of the cornea and the pigment cells of the skin contract under nervous excitation. We cannot suppose that although these are the only cells which have hitherto been brought under experimental observation, they are the only cells subject to nerve-influence. We may safely assume that wherever a nerve-fibre terminates, its action will be transformed into an excitation of the part. Habitually, however, motor-nerves are spoken of as muscle-nerves.90On Deduction, seeProblems: First Series, Vol. II. p. 15991I do not here touch upon the question as to whether these actions of the senses aresensations, because that question demands that we should first settle what isSensation. I may at once, however, say that what is ordinarily understood as a sensation ofcolor, or a sensation ofsound, is, in my opinion, not possible without the cerebrum. But the sensibility of the eye and ear is manifestly preserved.92It has been observed that removal of the cerebellum affects the pigment cells of the skin. No doubt other parts are also affected, but the changes have hitherto escaped observation.93Owsjannikowdescribes the results of removing carefully the cranial ganglia of the crayfish; and these effectsMeyerobserves to be identical with those which follow removal of the large claw of the crayfish!A. B. Meyer,Das Hemmungsnerven-system des Herzens, 1869, p. 23. Let me add that the phenomena described by M.Faivreas following the destruction of one subœsophageal ganglion in theDytiscus, are so little to be referred to the mere absence of the ganglion, that I find them not to occur when the whole head is removed.94Pflüger,Die Sensorischen Funktionen des Rückenmarks,1858.Auerbach,Günzburg’s Zeitschrift. Jahrgang IV. p. 486.Lewes,Leeds Meeting of British Association, 1858, andPhysiology of Common Life, 1860.This recognition of sensation, and even of volition, in spinal actions may be found in the writings ofWhytt,Unzer,Prochaska,Legallois, andMayo; but the establishment of the Reflex Theory had displaced it, and its revival dates fromPflüger.95Friedländer(Versuch über die innern Sinne, 1826, I. 77) declares it to be a rational necessity: “Die Annahme eines Nervenfluidums ist Nothwendigkeit der Vernunft.”96These terms and the conception they embody were proposed by me in 1859 in a paper “On the necessity of a reform in Nerve-physiology,” read at the Aberdeen meeting of the British Association, and were reproduced in thePhysiology of Common Life. (Prof.Owen, probably in forgetfulness of my suggestion, proposed “neuricity.”Lectures on the Comp. Anat. of Vertebrates, 1866, I. p. 318.) The terms were fortunate enough to meet with acceptance from some physiologists both in England and France; and the conception has been more widely accepted than the terms. The most distinguished approver was Prof.Vulpian. “Faute d’une meilleure détermination on peut, avec M. Lewes, donner à la propriété physiologique des fibres nerveuses le nom deneurilité; c’est là ce qui correspondra à la oontractilitè des fibres musculaires.”Leçons sur la physiologie du système nerveux, 1866, p. 220. He also adopted my suggestion (since modified) of Sensibility as the property of ganglionic cells. Compare alsoGavarret,Phénomènes physiques de la Vie, 1869, pp. 213 and 222.Taule,Notions sur la nature de la matière organisée, 1866, p. 131.Charles Robin,Anatomie et physiologie cellulaires, 1873, p. 166.By these channels, and by the German, Italian, Russian, Polish, and Hungarian translations of my work, the suggestions were carried over Europe, crept into scientific journals, and became known to writers who never heard of me. I only mention these facts lest the reader should suppose that my views had been anticipated by certain continental writers.97“La force nerveuse n’existe pas comme puissance independant des propriétés de tissu. Elle consiste en l’action des parties excités, sur les parties excitables, l’état de l’excitation des premières agissant comme impression ou stimulation sur les secondes.”—Landry,Traité des Paralysies, 1859, I. 142.98“Le système nerveux est tout à la fois l’origine des sensations et l’origine des mouvements. Mais est-ce par une propriété unique, ou par deux propriétés diverses qu’il détermine deux phénomènes aussi distincts!”Flourens,Recherches sur les propriétés et les fonctions du Système Nerveux, 1824, p. 1. He concludes that “la puissance nerveuse n’est pas unique; il n’y a pas une seule propriété, il y en a deux,” p. 24. In this he has been generally followed.99“I have raised and stretched the thick orbital nerve of horses on the handle of a scalpel, like a string on the bridge of a violin, without exciting the least sensation; but as soon as mechanical or chemical irritation had given rise to inflammation of the nerve a gentle touch caused violent pain.”—Romberg,Nervous Diseases(translated for the Sydenham Society), I. 10.100The experiments ofHaller,Sur la nature sensible et irritable des parties, I. 245; and the remarks ofProchaska,De Functionibus Systematis Nervosi(translated byLaycockin the volume published by theSydenham Society, p. 396), ought to have sufficed. See further on,Chap. V.101In mammals about three days, in birds four days, in frogs fourteen to twenty days.102Rutherford, inJournal of Anatomy, 1873, No. VIII. p. 331. (Fleischldenies that the nervein situhas different degrees of reaction.Sitzungsberichte der Wiener Akad., December, 1876.)103Munk, in theArchiv für Anat., 1860, p. 798.104Haller,Mémoires sur la nature sensible et irritable des parties.105Comptes Rendus, 1862, LIV. p. 965.106“J’espère vous convaincre que tous les éléments anatomiques des nerfs sensitifs, moteurs, vasomoteurs, et autres, ont les mêmes propriétés, et ne sont distincts que par leurs fonctions. Cette question est de la plus haute importance pour la physiologie générale. C’est celle qui domine toute la physiologie des fibres nerveuses.”—Vulpian,Leçons sur la Physiologie du Système Nerveux, p. 11.107Mr.James Andrews.108In the second number ofLa Revue Philosophique, Paris, 1876, I have treated this question of specific energies more at length than I could find space for in the present volume.109In 1859 I mentioned that if the nerves of a frog’s back be exposed by raising the skin, they may be pricked or even cut without sensible effect, although a slight prick on the skin will excite the nerves, and cause a reflex action. In 1870, Prof.Fickexpressed his astonishment at finding that after he had cut out a piece of the skin, leaving it attached to the body by a single nerve, electrical stimulation of this excised skin caused the frog to make the reflex movement of rubbing the irritated surface; whereas electrical stimulation of the nerve-trunk itself produced no reflex effect, only a twitching of a muscle.Pflüger’s Archiv, 1870, p. 327.Brown Séquardtries to establish a distinct species of nerves asconductorsof sensitive impressions, from those which areimpressionable. The facts on which he founds these two properties simply show that nerves are so disposed that the stimulus which excites them in one place fails in another. He could hardly maintain that a skin nerve contained impressionable fibres at its periphery, and only conducting fibres in its trunk! See his communication to the Royal Society,Proceedings, 1856; andLecturesin theLancet, 10th July, 1858.110In consequence of this observation some physiologists have maintained that Feeling or Consciousness never arises in cerebral activity, unless the thalami and the connected tracts are at the same time in action. I go further, and maintain that there is no Consciousness (in the restricted meaning of the term)unless the whole organism is involved. Cerebral or spinal activity will be activity of Sensibility; but this is only the basis of Consciousness.111“An unconscious sensation, which Lewes distinguishes from perception, is to me an inconceivable (ist für mich ein Unding).”—Schröder van der Kolk,Die Pathologie des Geistes-Krankheiten, p. 22.112By selective adaptation is meant the varying combination of motor impulses to suit the varying requirements of the effect to be produced. Physical mechanisms are limited to the performance of definite actions; sensitive mechanisms employ fluctuating combinations of elements in response to fluctuations of stimuli. The wheels, levers, springs, and valves of a machine cannot be differently combined according to varying degrees of the motor-force, as the nerves and muscles of an organism are differently combined by varying sensations. An automaton may be constructed to play on the violin, but it will only play the air to which it isset; it cannot vary the performance,—cannot play a false note, or throw in acrescendohere, alargothere, according to a caprice of feeling. We must admit that violinist has his delicate and changing movements guided by sensations, auditory and muscular; any interruption in the sensations would arrest the movements, which in truthincorporatethem. And yet it is well known that the violinist may perform while completely “unconscious.” I do not simply refer to the fact that his thoughts and attention may be elsewhere; I refer to such facts as are recorded in Pathology.Trousseau, for example, had an epileptic patient who was occasionally seized with attacks of complete unconsciousness while he was performing in the orchestra; yet, on reawakening to consciousness, he found that he had continued to play, had kept proper time, and played the proper notes.113Claude Bernard,Système Nerveux, 1858, I. 349.114Wordsworth,The Prelude.115“On peut dire que toujours un phénomène de mouvement reconnait pour point de départ une impression sensitive.”—Claude Bernard, I. 267.116Since this was written Prof.Michael Fosterand Mr.Dew Smithhave published their very important researches on the motions of the heart, which establish beyond a doubt that, in the molluscs at least, there is no co-operation of either centre or nerve.—Proceedings of the Royal Society, 18th March, 1875. (See also Studies from the Physiological Laboratory of Cambridge, Part II., 1876.) Mr. Foster knows that I had independently, and from a totally different line of research, arrived at the same conclusion respecting the heart’s movement.117Comptes Rendus de la Socíété de Biologie, 1847, I. 40. In 1856 he showed that not only were the muscles of the iris directly stimulated by light (and this not by its calorific or chemical rays), but that sixteen days after removal of the eye from the orbit, this effect was observable in the eel. Yet a very few days after extirpation of the eye the nerves are disintegrated.—Proceedings of the Royal Society, 1856, p. 234.Dondershas the following observations: “The movements of the iris are of two kinds—reflex and voluntary. Reflex action is exhibited as constriction of the pupil in consequence of the stimulus of incident light upon the retina. Fontana has shown that the light falling upon the iris produces no remarkable contraction. We have confirmed this result by causing the image of a small distant light to fall, by means of a convex lens, upon the iris, whereby, during slight perception of light, a doubtful contraction occurred, which gave way to a strong contraction so soon as the light entering the pupil excited a vivid perception. Nevertheless, the experiments of Harless and Budge have shown that even after death, so long as irritability remains, the pupil still contracts upon the continued action of light. Of the correctness of this we have satisfied ourselves. In a dog killed by loss of blood the one eye was closed, the other opened and turned to the light: after the lapse of an hour, the pupil of the opened eye was perceptibly smaller than that of the closed eye. The latter now remained also exposed to the light, and on the following day the diameter of both eyes was equal. The upper jaw, alone with the eyes, was taken out of some frogs; one eye was exposed to the light, while the other was covered with a closely folded piece of black paper: after the lapse of half an hour the pupil turned to the light was narrow, the other wide. But the latter also contracted almost immediately after the removal of the paper.”—Donders,On the Anomalies of Accommodation and Refraction of the Eye. Trans. of the New Sydenham Society, p. 572.118The experiment often fails, but I have seen it several times succeed.119Pflüger’s Archiv, 1872, p. 618.120See his Researches inPflüger’s Archiv, Bde.II. and IV.121D’Orbigny,Des Mollusques Vívants et fossils, p. 113.122Seaside Studies, 2d ed., p. 101.123Cited byBrown Séquard,Journal de la Physiologie, 1858, p. 359.124Dr.Norrishas recorded some striking observations in his paper on “Muscular Irritability” in theJournal of Anatomy, 1867, No. II. p. 217. Here is the only one I can find room for: “On taking up thedeadfrog and touching the limb (which during life had been paralysed by section of its nerve) with my finger,it was suddenly shot out as if alive. I placed the body down, and one or twoapparently spontaneous movementsof small extent afterwards occurred. On touching the skin gently with the point of a needle, by the slight pressure upon the muscle beneath, movements of the limb were also induced, but this high degree of exaltation very rapidly disappeared.”125See their papers in theArchiv für Psychiatrie, 1875, Bd. V. Heft 3.126This latter statement will be justified when I come to expound the Triple Process, which I have named thePsychological Spectrum.127FosterandBalfour,Elements of Embryology, 1874, Part I. p. 52.His,Untersuchungen über die erste Anlage des Wirbelthierleibes, 1868, p. 197.128They state that the cells of the epiblast are the results of direct segmentation, whereas the cells of the other layers are formed at a subsequent period, and are only indirectly results of segmentation. But if the observations ofKowalewskyare exact, this is not the case with the hypoblast of the Amphioxus, which is from the first identical with the epiblast.129Kölliker,Entwicklungsgeschichte des Menschen und der höheren Thiere, 1861, p. 71.130[According toBalfour’srecent observations, a large part of the muscular tissue is derived from the layer of the mesoblast belonging to the hypoblast.]131His,Untersuchungen, pp. 39, 40.132Quite recentlyOwsjannikowhas pointed out the termination of fibres in the phosphorescent cells of theLampyris Noctiluca. See his paper in theMémoires de l’Acad. de St. Petersbourg, 1868, XI. 17. These phosphorescent cells are said to be ganglion-cells byPanceri,Intorno della luce che emana dalle celleule nervose(Rendiconto della Accad. delle Scienze, April, 1872); and byEimer,Archiv für mikros. Anatomie, 1872, p. 653.Köllikeralso calls the phosphorescent organ a nervous organ. This is not to be interpreted as meaning that neurility is phosphorescence, but simply that in some nerve-cells there is phosphorescent matter, which is called into activity by stimulus of the nerves.133BidderundKupffer,Textur des Rückenmarks, 1857, p. 108. [What is said in the text has been rendered doubtful by the recent researches of Mr.F. Balfour,On the Development of the Spinal Nerves in Elasmobranch Fishes(Philos. Trans., Vol. CLXVI. Part I.), which show that in these fishes the ganglion has its origin in the spinal cord.]134Comp.Problem I.§130, with the remarks ofCharles Robin,Anatomie et Physiologie Cellulaires, 1873, p. 20.135Kleinenberg,Hydra; Eine Anatomisch-Entwickelungs-Untersuchung, 1872, p. 11.Eimer,Zoologische Studien auf Capri, 1873, p. 66.A similar formation is described by Dr.Allmanin theMyriothela; he says, however, that he has never been able to trace a direct continuity of the caudal processes of the cells with muscular fibrils. He believes that the processes make their way to the muscular layer through undifferentiated protoplasm.—Philos. Transactions, Vol. CLXV. Part II. p. 554.An intermediate stage between this neuro-muscular tissue and the two differentiated tissues seems presented in the Nematoid worms which have muscles that send off processes into which the nerves pass.Gegenbaurdeclares his inability to decide whether these processes are muscles or nerves.Bütschlithinks the nerve-process blends with the muscle-process.—Archiv für mikros. Anatomie, 1873, p. 89.136“The gray matter of the cord seems undoubtedly to be formed by a metamorphosis of the external cells of the epiblast of the neural tube, and is directly continuous with the epithelium; there being no strong line of demarcation between them.”—Op. cit., p. 185.137Robin,Anat. et Physiol. Cellulaires, p. 332.138Stilling,Bau der Nervenprimitiv-Fasern, 1856, p. 16.139“There was a time,” saysKölliker, “when I confidently believed that an hypothetical explanation of the arrangement of elements in the spinal cord could be grounded on a basis of fact; but the deeper my insight into the minute anatomy, the less my confidence became; and now I am persuaded that the time is not yet come to frame such an hypothesis.”—Gewebelehre, 5te Auf. 1867.140In the Gasteropoda the cells range from 220 μ to 3 μ (μ = 0,001 millimètre).141Haeckel,Müller’s Archiv, 1857.Leydig,Vom Bau des thierischen Körpers, 1864, I. 84.Robin,Anat. et Physiol. Cellulaires, p. 89. Should the observations ofHeitzmannbe confirmed, there would be ground for believing that neurine is normally fibrillated. He says that the living protoplasm in the Amœba, white blood-corpuscle, etc., is an excessively fine network, which condenses into granules at each contraction. (Cited in theJahresberichte über Anat. und Physiol., 1873, Bd. II.)Walther, who examined frozen brains, describes the cells as quite transparent at first, with very rare granules, but gradually while under observation the granules became more numerous.Centralblatt, 1868, p. 459. According toMauthner,Beiträge zur Kenntniss der morphologischen Elemente des Nervensystems, 1862, p. 41, neurine has three cardinal forms—transparent, finely granular, and coarsely granular.142Trinchese,Struttura del sistema nervoso dei Cefalopodi, Florence, 1868, p. 7.143An eminent friend of mine was one day insisting to me that the physiological postulate made itimpossiblefor a nerve-cell to be without its ingoing and outgoing fibres; and he was not a little astounded when I replied, “Come into my workroom and I will show you a thousand.”144EichhorstinVirchow’s Archiv, 1875, LXIV. p. 432.145Auerbach(Ueber einen Plexus Myentericus, 1862) describes the ganglia as filled with apolar cells, among which only a few are unipolar.Stieda(Centralnervensystem der Vögel, 1868) finds both apolar and unipolar cells in the spinal ganglia of birds.Axmann(De Gangliorum Systematis Structura penitiori, 1847) says the spinal cells are all unipolar.Schwalbe(Archiv für mikros. Anat., 1868) andCourvoisier(ibid., 1869) say the same. So alsoRanvier,Comptes Rendus, 1875.Kölliker(Gewebelehre) speaks decidedly in favor of both apolar and unipolar cells, but thinks the apolar are embryonic.Pagliani(Saggio sullo Stato attuale delle Cognizioni della Fisiologia intorno al Sistema nervoso, 1873), who represents the views ofMoleschott, admits the existence of apolar and unipolar cells. The authors just cited are those I happen to have before me during the rewriting of this chapter, and the list might easily be extended if needful.Auerbach,Bidder, andSchweigger-Seideldescribe unipolar cells which in some places present the aspect of bipolar cells simply because two cells lie together, their single poles having opposite directions. I will add that the bipolar cells do not really render the physiological interpretation a whit more easy than the unipolar, for they are simply cells which form enlargements in the course of the nerve-fibres.146When Dr.Bealesays “that it is probable no nerve-cell exists which has onlyone single fibreconnected with it” (Bioplasm, p. 186), he has no doubt this in his mind; since he would not, I presume, deny that there are cells each with a singleprocess.147Deiters,Untersuchungen über Gehirn und Rückenmark, 1865.148Archiv für mikros. Anat., 1869, p. 217. Compere alsoButzke,Archiv für Psychiatrie, 1872, p. 584.149Henle,Nervenlehre, 1871, p. 58, Fig. 21.150When men of such experience and skill asKölliker,Bidder,Goll, andLockhart Clarkedeclare that they have never seen a cell-process pass directly into a dark-bordered fibre in the anterior root, what are we to say to such figures and descriptions as those given in the works ofSchröder van der Kolk,Gratiolet, andLuys? Even did such arrangements exist, no transverse nor longitudinal section could display them, owing to the different planes at which the fibres enter, and the length and irregularity of their course.151Long after the text was written,Willigkpublished inVirchow’s Archiv, 1875, LXIV. p. 163, observations of anastomoses which evenKöllikeradmitted to be undeniable. Yet out of sixty-four preparations, amid hundreds of cells, he could only reckon seven cases of conjunction.152See the history given inStilling’slearned work,Ueber den Bau der Nervenprimitiv-Faser, p. 34; and compareMax Shultze,De Retinæ Structura, p. 8, andBau der Nasenschleimhaut, p. 66;Waldeyer, in theZeitschrift für rat. Med., 1863;ListerandTurner,Observations on the Structure of Nerve-Fibres, inQuarterly Micros. Journal, 1859;Ranvier, in theArchives de Physiologie, 1872.153Virchow’s Archiv, Bd. LXXII. p. 193.154Monthly Journal of Micros. Science, 1874, XI. p. 214.155Babuchin,Centralblatt, 1868, p. 756.156Even so eminent an authority asW. Krauseholds this both with regard to the varicose aspect and the double contour:Handbuch der menschlichen Anatomie, 1876, I. 367.Butschli, however, describes the nerves in a living Nematode as varicose:Archiv für Anat., 1873, p. 78; and I have somewhere met with an observation of the double contour being visible in the living animal.157Butzke,Archiv für Psychiatrie, 1872, p. 594, states that the granular substance has the chemical composition of myeline. If this be so, we may suppose the “fibrils of crystallization” to represent the coagulation of the substance which is in solution amid the myeline granules, and corresponds with the axis cylinder of a fibre. I may remark that in almost every good preparation nerve-cells will be found in which, while one process is distinctly granular, another is striated or even fibrillated.158Boll,Die Histiologie und Histiogenese der nervösen Centralorgane, in theArchiv für Psychiatrie, 1873, p. 47.159Stieda,Studien über das Centralnervensystem der Vögel, 1868, p. 65.Mauthner,Op. cit., p. 4.160TurnerandLister,Op. cit., p. 8.161Blessig,De Retinæ Structura, 1857.162Luys,Recherches sur le Système nerveux, 1865, p. 267. In a recent and remarkable treatise the student is informed that “plus une cellule est chargée d’un rôle purement mécanique plus elle est volumineuse; plus l’acte qu’elle produit tend à revêtir un caractère psychique plus elle est petite”; to move a limb theagitationof the cerebral cells mustmaterialize itselfmore and more, “Il a besoin de passer par des cellules, de moins en moins spirituelles et de plus en plus matérielles.... De même pour les cellules sensitives. L’impression extérieure va en se modifiant, en se spiritualisant, de la périphérie au centre.... Un phénomène de l’ordre spirituel ne sanrait devenir sans transition un phénomène d’ordre physique.” And what is this marvellous transition between spiritual and physical? It is the action of medium-sized cells which “travaillent la vibration reçue, la modifient de façon à lui ôter de son spiritualisme et à la rapprocher davantage des ébranlements physiques.” I will not name the estimable author, because he is simply restating what many others implicitly or explicitly teach; but I will only ask the reader to try and realize in thought the process thus described.163Schröder Van Der Kolk,Pathologie der Geisteskrankheiten, 1863, p. 69.164Wundt,Physiologische Psychologie, p. 261. In hisMechanik der Nerven, 2 Abth.(published just as this sheet is going to press), he shows that a stimulus is both retarded and weakened in its passage through a ganglion.165Trinchesealso says that the fibres “provengono dalle cellule enon son altro che i loro prolungamenti o poli.”—Op. cit., p. 13. An unequivocal example is seen in theTorpedo, where the large cells have each their prolongation continuing without interruption into the electrical organ. See the figure given byReichenheimin theArchiv für Anat., 1873, Heft VI.166Golgi,Sulla struttura della sostanza grizia del Cervello.Arndt,Archiv für mikros. Anat.1870, p. 176.Rindfleischalso traces these processes into the neuroglia (ibid., 1872, p. 453). “Deiters, Boddaert, and other observers have stated that one dark-bordered nerve-fibre enters each cell.... My own observations lead me to conclude thatallthe fibres are composed of the same material, but that one fibre does not divide until it has passed some distance from the cell, while others give off branches much closer to it.”—Beale,Bioplasm, p. 189.
86German anatomists divide this axis into trunk and crown (HirnstammandHirnmantel). There is convenience in this division. If we remove all the gray matter of the cerebrum, with all the white matter radiating from it, until we again come upon gray matter—and if we then cut the cerebellum from its descending strands of white matter—we shall have removed thecrown, and leave thetrunkremaining. This trunk is constituted by the corpora striata, nucleus lentiformis, optic thalami, corpora quadrigemina, crura cerebri, pons, medulla oblongata, and medulla spinalis. From this trunk all the organs of the body are directly innervated (except those innervated from the sympathetic?).
86German anatomists divide this axis into trunk and crown (HirnstammandHirnmantel). There is convenience in this division. If we remove all the gray matter of the cerebrum, with all the white matter radiating from it, until we again come upon gray matter—and if we then cut the cerebellum from its descending strands of white matter—we shall have removed thecrown, and leave thetrunkremaining. This trunk is constituted by the corpora striata, nucleus lentiformis, optic thalami, corpora quadrigemina, crura cerebri, pons, medulla oblongata, and medulla spinalis. From this trunk all the organs of the body are directly innervated (except those innervated from the sympathetic?).
87“On s’est préoccupé du rôle spécial que pouvaient jouer les ganglions périphériques situés dans le voisinage de certaines organes; et on a prétendu que les nerfs ne jouissaient de leur propriété d’agir sur ces organes qu’après avoir traversé ces ganglions. On avait admis que l’excitation portée sur le filet nerveux avant son entré dans le ganglion restait sans effet; que pour obtenir l’action excitatrice des fonctions de l’organe il fallait exciter le nerf entre lui et le ganglion voisin.”—Claude Bernard,Systéme Nerveux, II. 169. But on proceeding to verify these statements by experiment,Bernardis led to the conclusion, “que le ganglion n’a pas d’influence propre sur le mode de l’excitation transmise à l’organe.”I was delighted to find my opposition to the current teaching respecting the central functions of ganglionic cells thoroughly borne out by the elaborate researches ofSigmund Mayer(Archiv für Psychiatrie, Bd. VI. Heft 2). Having artificially produced such cells, he pertinently asks, How can we attribute central functions to cells which appear in the process of regeneration of a divided nerve! The error has its origin in the confusion of functions with properties.
87“On s’est préoccupé du rôle spécial que pouvaient jouer les ganglions périphériques situés dans le voisinage de certaines organes; et on a prétendu que les nerfs ne jouissaient de leur propriété d’agir sur ces organes qu’après avoir traversé ces ganglions. On avait admis que l’excitation portée sur le filet nerveux avant son entré dans le ganglion restait sans effet; que pour obtenir l’action excitatrice des fonctions de l’organe il fallait exciter le nerf entre lui et le ganglion voisin.”—Claude Bernard,Systéme Nerveux, II. 169. But on proceeding to verify these statements by experiment,Bernardis led to the conclusion, “que le ganglion n’a pas d’influence propre sur le mode de l’excitation transmise à l’organe.”
I was delighted to find my opposition to the current teaching respecting the central functions of ganglionic cells thoroughly borne out by the elaborate researches ofSigmund Mayer(Archiv für Psychiatrie, Bd. VI. Heft 2). Having artificially produced such cells, he pertinently asks, How can we attribute central functions to cells which appear in the process of regeneration of a divided nerve! The error has its origin in the confusion of functions with properties.
88It is often, though incorrectly, stated that every segment of an annulose animal has its separate ganglion. The fact is, that while the ganglia are usually fewer than the segments, they are sometimes more numerous.
88It is often, though incorrectly, stated that every segment of an annulose animal has its separate ganglion. The fact is, that while the ganglia are usually fewer than the segments, they are sometimes more numerous.
89It has been proved that the cells of the cornea and the pigment cells of the skin contract under nervous excitation. We cannot suppose that although these are the only cells which have hitherto been brought under experimental observation, they are the only cells subject to nerve-influence. We may safely assume that wherever a nerve-fibre terminates, its action will be transformed into an excitation of the part. Habitually, however, motor-nerves are spoken of as muscle-nerves.
89It has been proved that the cells of the cornea and the pigment cells of the skin contract under nervous excitation. We cannot suppose that although these are the only cells which have hitherto been brought under experimental observation, they are the only cells subject to nerve-influence. We may safely assume that wherever a nerve-fibre terminates, its action will be transformed into an excitation of the part. Habitually, however, motor-nerves are spoken of as muscle-nerves.
90On Deduction, seeProblems: First Series, Vol. II. p. 159
90On Deduction, seeProblems: First Series, Vol. II. p. 159
91I do not here touch upon the question as to whether these actions of the senses aresensations, because that question demands that we should first settle what isSensation. I may at once, however, say that what is ordinarily understood as a sensation ofcolor, or a sensation ofsound, is, in my opinion, not possible without the cerebrum. But the sensibility of the eye and ear is manifestly preserved.
91I do not here touch upon the question as to whether these actions of the senses aresensations, because that question demands that we should first settle what isSensation. I may at once, however, say that what is ordinarily understood as a sensation ofcolor, or a sensation ofsound, is, in my opinion, not possible without the cerebrum. But the sensibility of the eye and ear is manifestly preserved.
92It has been observed that removal of the cerebellum affects the pigment cells of the skin. No doubt other parts are also affected, but the changes have hitherto escaped observation.
92It has been observed that removal of the cerebellum affects the pigment cells of the skin. No doubt other parts are also affected, but the changes have hitherto escaped observation.
93Owsjannikowdescribes the results of removing carefully the cranial ganglia of the crayfish; and these effectsMeyerobserves to be identical with those which follow removal of the large claw of the crayfish!A. B. Meyer,Das Hemmungsnerven-system des Herzens, 1869, p. 23. Let me add that the phenomena described by M.Faivreas following the destruction of one subœsophageal ganglion in theDytiscus, are so little to be referred to the mere absence of the ganglion, that I find them not to occur when the whole head is removed.
93Owsjannikowdescribes the results of removing carefully the cranial ganglia of the crayfish; and these effectsMeyerobserves to be identical with those which follow removal of the large claw of the crayfish!A. B. Meyer,Das Hemmungsnerven-system des Herzens, 1869, p. 23. Let me add that the phenomena described by M.Faivreas following the destruction of one subœsophageal ganglion in theDytiscus, are so little to be referred to the mere absence of the ganglion, that I find them not to occur when the whole head is removed.
94Pflüger,Die Sensorischen Funktionen des Rückenmarks,1858.Auerbach,Günzburg’s Zeitschrift. Jahrgang IV. p. 486.Lewes,Leeds Meeting of British Association, 1858, andPhysiology of Common Life, 1860.This recognition of sensation, and even of volition, in spinal actions may be found in the writings ofWhytt,Unzer,Prochaska,Legallois, andMayo; but the establishment of the Reflex Theory had displaced it, and its revival dates fromPflüger.
94Pflüger,Die Sensorischen Funktionen des Rückenmarks,1858.Auerbach,Günzburg’s Zeitschrift. Jahrgang IV. p. 486.Lewes,Leeds Meeting of British Association, 1858, andPhysiology of Common Life, 1860.
This recognition of sensation, and even of volition, in spinal actions may be found in the writings ofWhytt,Unzer,Prochaska,Legallois, andMayo; but the establishment of the Reflex Theory had displaced it, and its revival dates fromPflüger.
95Friedländer(Versuch über die innern Sinne, 1826, I. 77) declares it to be a rational necessity: “Die Annahme eines Nervenfluidums ist Nothwendigkeit der Vernunft.”
95Friedländer(Versuch über die innern Sinne, 1826, I. 77) declares it to be a rational necessity: “Die Annahme eines Nervenfluidums ist Nothwendigkeit der Vernunft.”
96These terms and the conception they embody were proposed by me in 1859 in a paper “On the necessity of a reform in Nerve-physiology,” read at the Aberdeen meeting of the British Association, and were reproduced in thePhysiology of Common Life. (Prof.Owen, probably in forgetfulness of my suggestion, proposed “neuricity.”Lectures on the Comp. Anat. of Vertebrates, 1866, I. p. 318.) The terms were fortunate enough to meet with acceptance from some physiologists both in England and France; and the conception has been more widely accepted than the terms. The most distinguished approver was Prof.Vulpian. “Faute d’une meilleure détermination on peut, avec M. Lewes, donner à la propriété physiologique des fibres nerveuses le nom deneurilité; c’est là ce qui correspondra à la oontractilitè des fibres musculaires.”Leçons sur la physiologie du système nerveux, 1866, p. 220. He also adopted my suggestion (since modified) of Sensibility as the property of ganglionic cells. Compare alsoGavarret,Phénomènes physiques de la Vie, 1869, pp. 213 and 222.Taule,Notions sur la nature de la matière organisée, 1866, p. 131.Charles Robin,Anatomie et physiologie cellulaires, 1873, p. 166.By these channels, and by the German, Italian, Russian, Polish, and Hungarian translations of my work, the suggestions were carried over Europe, crept into scientific journals, and became known to writers who never heard of me. I only mention these facts lest the reader should suppose that my views had been anticipated by certain continental writers.
96These terms and the conception they embody were proposed by me in 1859 in a paper “On the necessity of a reform in Nerve-physiology,” read at the Aberdeen meeting of the British Association, and were reproduced in thePhysiology of Common Life. (Prof.Owen, probably in forgetfulness of my suggestion, proposed “neuricity.”Lectures on the Comp. Anat. of Vertebrates, 1866, I. p. 318.) The terms were fortunate enough to meet with acceptance from some physiologists both in England and France; and the conception has been more widely accepted than the terms. The most distinguished approver was Prof.Vulpian. “Faute d’une meilleure détermination on peut, avec M. Lewes, donner à la propriété physiologique des fibres nerveuses le nom deneurilité; c’est là ce qui correspondra à la oontractilitè des fibres musculaires.”Leçons sur la physiologie du système nerveux, 1866, p. 220. He also adopted my suggestion (since modified) of Sensibility as the property of ganglionic cells. Compare alsoGavarret,Phénomènes physiques de la Vie, 1869, pp. 213 and 222.Taule,Notions sur la nature de la matière organisée, 1866, p. 131.Charles Robin,Anatomie et physiologie cellulaires, 1873, p. 166.
By these channels, and by the German, Italian, Russian, Polish, and Hungarian translations of my work, the suggestions were carried over Europe, crept into scientific journals, and became known to writers who never heard of me. I only mention these facts lest the reader should suppose that my views had been anticipated by certain continental writers.
97“La force nerveuse n’existe pas comme puissance independant des propriétés de tissu. Elle consiste en l’action des parties excités, sur les parties excitables, l’état de l’excitation des premières agissant comme impression ou stimulation sur les secondes.”—Landry,Traité des Paralysies, 1859, I. 142.
97“La force nerveuse n’existe pas comme puissance independant des propriétés de tissu. Elle consiste en l’action des parties excités, sur les parties excitables, l’état de l’excitation des premières agissant comme impression ou stimulation sur les secondes.”—Landry,Traité des Paralysies, 1859, I. 142.
98“Le système nerveux est tout à la fois l’origine des sensations et l’origine des mouvements. Mais est-ce par une propriété unique, ou par deux propriétés diverses qu’il détermine deux phénomènes aussi distincts!”Flourens,Recherches sur les propriétés et les fonctions du Système Nerveux, 1824, p. 1. He concludes that “la puissance nerveuse n’est pas unique; il n’y a pas une seule propriété, il y en a deux,” p. 24. In this he has been generally followed.
98“Le système nerveux est tout à la fois l’origine des sensations et l’origine des mouvements. Mais est-ce par une propriété unique, ou par deux propriétés diverses qu’il détermine deux phénomènes aussi distincts!”Flourens,Recherches sur les propriétés et les fonctions du Système Nerveux, 1824, p. 1. He concludes that “la puissance nerveuse n’est pas unique; il n’y a pas une seule propriété, il y en a deux,” p. 24. In this he has been generally followed.
99“I have raised and stretched the thick orbital nerve of horses on the handle of a scalpel, like a string on the bridge of a violin, without exciting the least sensation; but as soon as mechanical or chemical irritation had given rise to inflammation of the nerve a gentle touch caused violent pain.”—Romberg,Nervous Diseases(translated for the Sydenham Society), I. 10.
99“I have raised and stretched the thick orbital nerve of horses on the handle of a scalpel, like a string on the bridge of a violin, without exciting the least sensation; but as soon as mechanical or chemical irritation had given rise to inflammation of the nerve a gentle touch caused violent pain.”—Romberg,Nervous Diseases(translated for the Sydenham Society), I. 10.
100The experiments ofHaller,Sur la nature sensible et irritable des parties, I. 245; and the remarks ofProchaska,De Functionibus Systematis Nervosi(translated byLaycockin the volume published by theSydenham Society, p. 396), ought to have sufficed. See further on,Chap. V.
100The experiments ofHaller,Sur la nature sensible et irritable des parties, I. 245; and the remarks ofProchaska,De Functionibus Systematis Nervosi(translated byLaycockin the volume published by theSydenham Society, p. 396), ought to have sufficed. See further on,Chap. V.
101In mammals about three days, in birds four days, in frogs fourteen to twenty days.
101In mammals about three days, in birds four days, in frogs fourteen to twenty days.
102Rutherford, inJournal of Anatomy, 1873, No. VIII. p. 331. (Fleischldenies that the nervein situhas different degrees of reaction.Sitzungsberichte der Wiener Akad., December, 1876.)
102Rutherford, inJournal of Anatomy, 1873, No. VIII. p. 331. (Fleischldenies that the nervein situhas different degrees of reaction.Sitzungsberichte der Wiener Akad., December, 1876.)
103Munk, in theArchiv für Anat., 1860, p. 798.
103Munk, in theArchiv für Anat., 1860, p. 798.
104Haller,Mémoires sur la nature sensible et irritable des parties.
104Haller,Mémoires sur la nature sensible et irritable des parties.
105Comptes Rendus, 1862, LIV. p. 965.
105Comptes Rendus, 1862, LIV. p. 965.
106“J’espère vous convaincre que tous les éléments anatomiques des nerfs sensitifs, moteurs, vasomoteurs, et autres, ont les mêmes propriétés, et ne sont distincts que par leurs fonctions. Cette question est de la plus haute importance pour la physiologie générale. C’est celle qui domine toute la physiologie des fibres nerveuses.”—Vulpian,Leçons sur la Physiologie du Système Nerveux, p. 11.
106“J’espère vous convaincre que tous les éléments anatomiques des nerfs sensitifs, moteurs, vasomoteurs, et autres, ont les mêmes propriétés, et ne sont distincts que par leurs fonctions. Cette question est de la plus haute importance pour la physiologie générale. C’est celle qui domine toute la physiologie des fibres nerveuses.”—Vulpian,Leçons sur la Physiologie du Système Nerveux, p. 11.
107Mr.James Andrews.
107Mr.James Andrews.
108In the second number ofLa Revue Philosophique, Paris, 1876, I have treated this question of specific energies more at length than I could find space for in the present volume.
108In the second number ofLa Revue Philosophique, Paris, 1876, I have treated this question of specific energies more at length than I could find space for in the present volume.
109In 1859 I mentioned that if the nerves of a frog’s back be exposed by raising the skin, they may be pricked or even cut without sensible effect, although a slight prick on the skin will excite the nerves, and cause a reflex action. In 1870, Prof.Fickexpressed his astonishment at finding that after he had cut out a piece of the skin, leaving it attached to the body by a single nerve, electrical stimulation of this excised skin caused the frog to make the reflex movement of rubbing the irritated surface; whereas electrical stimulation of the nerve-trunk itself produced no reflex effect, only a twitching of a muscle.Pflüger’s Archiv, 1870, p. 327.Brown Séquardtries to establish a distinct species of nerves asconductorsof sensitive impressions, from those which areimpressionable. The facts on which he founds these two properties simply show that nerves are so disposed that the stimulus which excites them in one place fails in another. He could hardly maintain that a skin nerve contained impressionable fibres at its periphery, and only conducting fibres in its trunk! See his communication to the Royal Society,Proceedings, 1856; andLecturesin theLancet, 10th July, 1858.
109In 1859 I mentioned that if the nerves of a frog’s back be exposed by raising the skin, they may be pricked or even cut without sensible effect, although a slight prick on the skin will excite the nerves, and cause a reflex action. In 1870, Prof.Fickexpressed his astonishment at finding that after he had cut out a piece of the skin, leaving it attached to the body by a single nerve, electrical stimulation of this excised skin caused the frog to make the reflex movement of rubbing the irritated surface; whereas electrical stimulation of the nerve-trunk itself produced no reflex effect, only a twitching of a muscle.Pflüger’s Archiv, 1870, p. 327.Brown Séquardtries to establish a distinct species of nerves asconductorsof sensitive impressions, from those which areimpressionable. The facts on which he founds these two properties simply show that nerves are so disposed that the stimulus which excites them in one place fails in another. He could hardly maintain that a skin nerve contained impressionable fibres at its periphery, and only conducting fibres in its trunk! See his communication to the Royal Society,Proceedings, 1856; andLecturesin theLancet, 10th July, 1858.
110In consequence of this observation some physiologists have maintained that Feeling or Consciousness never arises in cerebral activity, unless the thalami and the connected tracts are at the same time in action. I go further, and maintain that there is no Consciousness (in the restricted meaning of the term)unless the whole organism is involved. Cerebral or spinal activity will be activity of Sensibility; but this is only the basis of Consciousness.
110In consequence of this observation some physiologists have maintained that Feeling or Consciousness never arises in cerebral activity, unless the thalami and the connected tracts are at the same time in action. I go further, and maintain that there is no Consciousness (in the restricted meaning of the term)unless the whole organism is involved. Cerebral or spinal activity will be activity of Sensibility; but this is only the basis of Consciousness.
111“An unconscious sensation, which Lewes distinguishes from perception, is to me an inconceivable (ist für mich ein Unding).”—Schröder van der Kolk,Die Pathologie des Geistes-Krankheiten, p. 22.
111“An unconscious sensation, which Lewes distinguishes from perception, is to me an inconceivable (ist für mich ein Unding).”—Schröder van der Kolk,Die Pathologie des Geistes-Krankheiten, p. 22.
112By selective adaptation is meant the varying combination of motor impulses to suit the varying requirements of the effect to be produced. Physical mechanisms are limited to the performance of definite actions; sensitive mechanisms employ fluctuating combinations of elements in response to fluctuations of stimuli. The wheels, levers, springs, and valves of a machine cannot be differently combined according to varying degrees of the motor-force, as the nerves and muscles of an organism are differently combined by varying sensations. An automaton may be constructed to play on the violin, but it will only play the air to which it isset; it cannot vary the performance,—cannot play a false note, or throw in acrescendohere, alargothere, according to a caprice of feeling. We must admit that violinist has his delicate and changing movements guided by sensations, auditory and muscular; any interruption in the sensations would arrest the movements, which in truthincorporatethem. And yet it is well known that the violinist may perform while completely “unconscious.” I do not simply refer to the fact that his thoughts and attention may be elsewhere; I refer to such facts as are recorded in Pathology.Trousseau, for example, had an epileptic patient who was occasionally seized with attacks of complete unconsciousness while he was performing in the orchestra; yet, on reawakening to consciousness, he found that he had continued to play, had kept proper time, and played the proper notes.
112By selective adaptation is meant the varying combination of motor impulses to suit the varying requirements of the effect to be produced. Physical mechanisms are limited to the performance of definite actions; sensitive mechanisms employ fluctuating combinations of elements in response to fluctuations of stimuli. The wheels, levers, springs, and valves of a machine cannot be differently combined according to varying degrees of the motor-force, as the nerves and muscles of an organism are differently combined by varying sensations. An automaton may be constructed to play on the violin, but it will only play the air to which it isset; it cannot vary the performance,—cannot play a false note, or throw in acrescendohere, alargothere, according to a caprice of feeling. We must admit that violinist has his delicate and changing movements guided by sensations, auditory and muscular; any interruption in the sensations would arrest the movements, which in truthincorporatethem. And yet it is well known that the violinist may perform while completely “unconscious.” I do not simply refer to the fact that his thoughts and attention may be elsewhere; I refer to such facts as are recorded in Pathology.Trousseau, for example, had an epileptic patient who was occasionally seized with attacks of complete unconsciousness while he was performing in the orchestra; yet, on reawakening to consciousness, he found that he had continued to play, had kept proper time, and played the proper notes.
113Claude Bernard,Système Nerveux, 1858, I. 349.
113Claude Bernard,Système Nerveux, 1858, I. 349.
114Wordsworth,The Prelude.
114Wordsworth,The Prelude.
115“On peut dire que toujours un phénomène de mouvement reconnait pour point de départ une impression sensitive.”—Claude Bernard, I. 267.
115“On peut dire que toujours un phénomène de mouvement reconnait pour point de départ une impression sensitive.”—Claude Bernard, I. 267.
116Since this was written Prof.Michael Fosterand Mr.Dew Smithhave published their very important researches on the motions of the heart, which establish beyond a doubt that, in the molluscs at least, there is no co-operation of either centre or nerve.—Proceedings of the Royal Society, 18th March, 1875. (See also Studies from the Physiological Laboratory of Cambridge, Part II., 1876.) Mr. Foster knows that I had independently, and from a totally different line of research, arrived at the same conclusion respecting the heart’s movement.
116Since this was written Prof.Michael Fosterand Mr.Dew Smithhave published their very important researches on the motions of the heart, which establish beyond a doubt that, in the molluscs at least, there is no co-operation of either centre or nerve.—Proceedings of the Royal Society, 18th March, 1875. (See also Studies from the Physiological Laboratory of Cambridge, Part II., 1876.) Mr. Foster knows that I had independently, and from a totally different line of research, arrived at the same conclusion respecting the heart’s movement.
117Comptes Rendus de la Socíété de Biologie, 1847, I. 40. In 1856 he showed that not only were the muscles of the iris directly stimulated by light (and this not by its calorific or chemical rays), but that sixteen days after removal of the eye from the orbit, this effect was observable in the eel. Yet a very few days after extirpation of the eye the nerves are disintegrated.—Proceedings of the Royal Society, 1856, p. 234.Dondershas the following observations: “The movements of the iris are of two kinds—reflex and voluntary. Reflex action is exhibited as constriction of the pupil in consequence of the stimulus of incident light upon the retina. Fontana has shown that the light falling upon the iris produces no remarkable contraction. We have confirmed this result by causing the image of a small distant light to fall, by means of a convex lens, upon the iris, whereby, during slight perception of light, a doubtful contraction occurred, which gave way to a strong contraction so soon as the light entering the pupil excited a vivid perception. Nevertheless, the experiments of Harless and Budge have shown that even after death, so long as irritability remains, the pupil still contracts upon the continued action of light. Of the correctness of this we have satisfied ourselves. In a dog killed by loss of blood the one eye was closed, the other opened and turned to the light: after the lapse of an hour, the pupil of the opened eye was perceptibly smaller than that of the closed eye. The latter now remained also exposed to the light, and on the following day the diameter of both eyes was equal. The upper jaw, alone with the eyes, was taken out of some frogs; one eye was exposed to the light, while the other was covered with a closely folded piece of black paper: after the lapse of half an hour the pupil turned to the light was narrow, the other wide. But the latter also contracted almost immediately after the removal of the paper.”—Donders,On the Anomalies of Accommodation and Refraction of the Eye. Trans. of the New Sydenham Society, p. 572.
117Comptes Rendus de la Socíété de Biologie, 1847, I. 40. In 1856 he showed that not only were the muscles of the iris directly stimulated by light (and this not by its calorific or chemical rays), but that sixteen days after removal of the eye from the orbit, this effect was observable in the eel. Yet a very few days after extirpation of the eye the nerves are disintegrated.—Proceedings of the Royal Society, 1856, p. 234.
Dondershas the following observations: “The movements of the iris are of two kinds—reflex and voluntary. Reflex action is exhibited as constriction of the pupil in consequence of the stimulus of incident light upon the retina. Fontana has shown that the light falling upon the iris produces no remarkable contraction. We have confirmed this result by causing the image of a small distant light to fall, by means of a convex lens, upon the iris, whereby, during slight perception of light, a doubtful contraction occurred, which gave way to a strong contraction so soon as the light entering the pupil excited a vivid perception. Nevertheless, the experiments of Harless and Budge have shown that even after death, so long as irritability remains, the pupil still contracts upon the continued action of light. Of the correctness of this we have satisfied ourselves. In a dog killed by loss of blood the one eye was closed, the other opened and turned to the light: after the lapse of an hour, the pupil of the opened eye was perceptibly smaller than that of the closed eye. The latter now remained also exposed to the light, and on the following day the diameter of both eyes was equal. The upper jaw, alone with the eyes, was taken out of some frogs; one eye was exposed to the light, while the other was covered with a closely folded piece of black paper: after the lapse of half an hour the pupil turned to the light was narrow, the other wide. But the latter also contracted almost immediately after the removal of the paper.”—Donders,On the Anomalies of Accommodation and Refraction of the Eye. Trans. of the New Sydenham Society, p. 572.
118The experiment often fails, but I have seen it several times succeed.
118The experiment often fails, but I have seen it several times succeed.
119Pflüger’s Archiv, 1872, p. 618.
119Pflüger’s Archiv, 1872, p. 618.
120See his Researches inPflüger’s Archiv, Bde.II. and IV.
120See his Researches inPflüger’s Archiv, Bde.II. and IV.
121D’Orbigny,Des Mollusques Vívants et fossils, p. 113.
121D’Orbigny,Des Mollusques Vívants et fossils, p. 113.
122Seaside Studies, 2d ed., p. 101.
122Seaside Studies, 2d ed., p. 101.
123Cited byBrown Séquard,Journal de la Physiologie, 1858, p. 359.
123Cited byBrown Séquard,Journal de la Physiologie, 1858, p. 359.
124Dr.Norrishas recorded some striking observations in his paper on “Muscular Irritability” in theJournal of Anatomy, 1867, No. II. p. 217. Here is the only one I can find room for: “On taking up thedeadfrog and touching the limb (which during life had been paralysed by section of its nerve) with my finger,it was suddenly shot out as if alive. I placed the body down, and one or twoapparently spontaneous movementsof small extent afterwards occurred. On touching the skin gently with the point of a needle, by the slight pressure upon the muscle beneath, movements of the limb were also induced, but this high degree of exaltation very rapidly disappeared.”
124Dr.Norrishas recorded some striking observations in his paper on “Muscular Irritability” in theJournal of Anatomy, 1867, No. II. p. 217. Here is the only one I can find room for: “On taking up thedeadfrog and touching the limb (which during life had been paralysed by section of its nerve) with my finger,it was suddenly shot out as if alive. I placed the body down, and one or twoapparently spontaneous movementsof small extent afterwards occurred. On touching the skin gently with the point of a needle, by the slight pressure upon the muscle beneath, movements of the limb were also induced, but this high degree of exaltation very rapidly disappeared.”
125See their papers in theArchiv für Psychiatrie, 1875, Bd. V. Heft 3.
125See their papers in theArchiv für Psychiatrie, 1875, Bd. V. Heft 3.
126This latter statement will be justified when I come to expound the Triple Process, which I have named thePsychological Spectrum.
126This latter statement will be justified when I come to expound the Triple Process, which I have named thePsychological Spectrum.
127FosterandBalfour,Elements of Embryology, 1874, Part I. p. 52.His,Untersuchungen über die erste Anlage des Wirbelthierleibes, 1868, p. 197.
127FosterandBalfour,Elements of Embryology, 1874, Part I. p. 52.His,Untersuchungen über die erste Anlage des Wirbelthierleibes, 1868, p. 197.
128They state that the cells of the epiblast are the results of direct segmentation, whereas the cells of the other layers are formed at a subsequent period, and are only indirectly results of segmentation. But if the observations ofKowalewskyare exact, this is not the case with the hypoblast of the Amphioxus, which is from the first identical with the epiblast.
128They state that the cells of the epiblast are the results of direct segmentation, whereas the cells of the other layers are formed at a subsequent period, and are only indirectly results of segmentation. But if the observations ofKowalewskyare exact, this is not the case with the hypoblast of the Amphioxus, which is from the first identical with the epiblast.
129Kölliker,Entwicklungsgeschichte des Menschen und der höheren Thiere, 1861, p. 71.
129Kölliker,Entwicklungsgeschichte des Menschen und der höheren Thiere, 1861, p. 71.
130[According toBalfour’srecent observations, a large part of the muscular tissue is derived from the layer of the mesoblast belonging to the hypoblast.]
130[According toBalfour’srecent observations, a large part of the muscular tissue is derived from the layer of the mesoblast belonging to the hypoblast.]
131His,Untersuchungen, pp. 39, 40.
131His,Untersuchungen, pp. 39, 40.
132Quite recentlyOwsjannikowhas pointed out the termination of fibres in the phosphorescent cells of theLampyris Noctiluca. See his paper in theMémoires de l’Acad. de St. Petersbourg, 1868, XI. 17. These phosphorescent cells are said to be ganglion-cells byPanceri,Intorno della luce che emana dalle celleule nervose(Rendiconto della Accad. delle Scienze, April, 1872); and byEimer,Archiv für mikros. Anatomie, 1872, p. 653.Köllikeralso calls the phosphorescent organ a nervous organ. This is not to be interpreted as meaning that neurility is phosphorescence, but simply that in some nerve-cells there is phosphorescent matter, which is called into activity by stimulus of the nerves.
132Quite recentlyOwsjannikowhas pointed out the termination of fibres in the phosphorescent cells of theLampyris Noctiluca. See his paper in theMémoires de l’Acad. de St. Petersbourg, 1868, XI. 17. These phosphorescent cells are said to be ganglion-cells byPanceri,Intorno della luce che emana dalle celleule nervose(Rendiconto della Accad. delle Scienze, April, 1872); and byEimer,Archiv für mikros. Anatomie, 1872, p. 653.Köllikeralso calls the phosphorescent organ a nervous organ. This is not to be interpreted as meaning that neurility is phosphorescence, but simply that in some nerve-cells there is phosphorescent matter, which is called into activity by stimulus of the nerves.
133BidderundKupffer,Textur des Rückenmarks, 1857, p. 108. [What is said in the text has been rendered doubtful by the recent researches of Mr.F. Balfour,On the Development of the Spinal Nerves in Elasmobranch Fishes(Philos. Trans., Vol. CLXVI. Part I.), which show that in these fishes the ganglion has its origin in the spinal cord.]
133BidderundKupffer,Textur des Rückenmarks, 1857, p. 108. [What is said in the text has been rendered doubtful by the recent researches of Mr.F. Balfour,On the Development of the Spinal Nerves in Elasmobranch Fishes(Philos. Trans., Vol. CLXVI. Part I.), which show that in these fishes the ganglion has its origin in the spinal cord.]
134Comp.Problem I.§130, with the remarks ofCharles Robin,Anatomie et Physiologie Cellulaires, 1873, p. 20.
134Comp.Problem I.§130, with the remarks ofCharles Robin,Anatomie et Physiologie Cellulaires, 1873, p. 20.
135Kleinenberg,Hydra; Eine Anatomisch-Entwickelungs-Untersuchung, 1872, p. 11.Eimer,Zoologische Studien auf Capri, 1873, p. 66.A similar formation is described by Dr.Allmanin theMyriothela; he says, however, that he has never been able to trace a direct continuity of the caudal processes of the cells with muscular fibrils. He believes that the processes make their way to the muscular layer through undifferentiated protoplasm.—Philos. Transactions, Vol. CLXV. Part II. p. 554.An intermediate stage between this neuro-muscular tissue and the two differentiated tissues seems presented in the Nematoid worms which have muscles that send off processes into which the nerves pass.Gegenbaurdeclares his inability to decide whether these processes are muscles or nerves.Bütschlithinks the nerve-process blends with the muscle-process.—Archiv für mikros. Anatomie, 1873, p. 89.
135Kleinenberg,Hydra; Eine Anatomisch-Entwickelungs-Untersuchung, 1872, p. 11.Eimer,Zoologische Studien auf Capri, 1873, p. 66.
A similar formation is described by Dr.Allmanin theMyriothela; he says, however, that he has never been able to trace a direct continuity of the caudal processes of the cells with muscular fibrils. He believes that the processes make their way to the muscular layer through undifferentiated protoplasm.—Philos. Transactions, Vol. CLXV. Part II. p. 554.
An intermediate stage between this neuro-muscular tissue and the two differentiated tissues seems presented in the Nematoid worms which have muscles that send off processes into which the nerves pass.Gegenbaurdeclares his inability to decide whether these processes are muscles or nerves.Bütschlithinks the nerve-process blends with the muscle-process.—Archiv für mikros. Anatomie, 1873, p. 89.
136“The gray matter of the cord seems undoubtedly to be formed by a metamorphosis of the external cells of the epiblast of the neural tube, and is directly continuous with the epithelium; there being no strong line of demarcation between them.”—Op. cit., p. 185.
136“The gray matter of the cord seems undoubtedly to be formed by a metamorphosis of the external cells of the epiblast of the neural tube, and is directly continuous with the epithelium; there being no strong line of demarcation between them.”—Op. cit., p. 185.
137Robin,Anat. et Physiol. Cellulaires, p. 332.
137Robin,Anat. et Physiol. Cellulaires, p. 332.
138Stilling,Bau der Nervenprimitiv-Fasern, 1856, p. 16.
138Stilling,Bau der Nervenprimitiv-Fasern, 1856, p. 16.
139“There was a time,” saysKölliker, “when I confidently believed that an hypothetical explanation of the arrangement of elements in the spinal cord could be grounded on a basis of fact; but the deeper my insight into the minute anatomy, the less my confidence became; and now I am persuaded that the time is not yet come to frame such an hypothesis.”—Gewebelehre, 5te Auf. 1867.
139“There was a time,” saysKölliker, “when I confidently believed that an hypothetical explanation of the arrangement of elements in the spinal cord could be grounded on a basis of fact; but the deeper my insight into the minute anatomy, the less my confidence became; and now I am persuaded that the time is not yet come to frame such an hypothesis.”—Gewebelehre, 5te Auf. 1867.
140In the Gasteropoda the cells range from 220 μ to 3 μ (μ = 0,001 millimètre).
140In the Gasteropoda the cells range from 220 μ to 3 μ (μ = 0,001 millimètre).
141Haeckel,Müller’s Archiv, 1857.Leydig,Vom Bau des thierischen Körpers, 1864, I. 84.Robin,Anat. et Physiol. Cellulaires, p. 89. Should the observations ofHeitzmannbe confirmed, there would be ground for believing that neurine is normally fibrillated. He says that the living protoplasm in the Amœba, white blood-corpuscle, etc., is an excessively fine network, which condenses into granules at each contraction. (Cited in theJahresberichte über Anat. und Physiol., 1873, Bd. II.)Walther, who examined frozen brains, describes the cells as quite transparent at first, with very rare granules, but gradually while under observation the granules became more numerous.Centralblatt, 1868, p. 459. According toMauthner,Beiträge zur Kenntniss der morphologischen Elemente des Nervensystems, 1862, p. 41, neurine has three cardinal forms—transparent, finely granular, and coarsely granular.
141Haeckel,Müller’s Archiv, 1857.Leydig,Vom Bau des thierischen Körpers, 1864, I. 84.Robin,Anat. et Physiol. Cellulaires, p. 89. Should the observations ofHeitzmannbe confirmed, there would be ground for believing that neurine is normally fibrillated. He says that the living protoplasm in the Amœba, white blood-corpuscle, etc., is an excessively fine network, which condenses into granules at each contraction. (Cited in theJahresberichte über Anat. und Physiol., 1873, Bd. II.)Walther, who examined frozen brains, describes the cells as quite transparent at first, with very rare granules, but gradually while under observation the granules became more numerous.Centralblatt, 1868, p. 459. According toMauthner,Beiträge zur Kenntniss der morphologischen Elemente des Nervensystems, 1862, p. 41, neurine has three cardinal forms—transparent, finely granular, and coarsely granular.
142Trinchese,Struttura del sistema nervoso dei Cefalopodi, Florence, 1868, p. 7.
142Trinchese,Struttura del sistema nervoso dei Cefalopodi, Florence, 1868, p. 7.
143An eminent friend of mine was one day insisting to me that the physiological postulate made itimpossiblefor a nerve-cell to be without its ingoing and outgoing fibres; and he was not a little astounded when I replied, “Come into my workroom and I will show you a thousand.”
143An eminent friend of mine was one day insisting to me that the physiological postulate made itimpossiblefor a nerve-cell to be without its ingoing and outgoing fibres; and he was not a little astounded when I replied, “Come into my workroom and I will show you a thousand.”
144EichhorstinVirchow’s Archiv, 1875, LXIV. p. 432.
144EichhorstinVirchow’s Archiv, 1875, LXIV. p. 432.
145Auerbach(Ueber einen Plexus Myentericus, 1862) describes the ganglia as filled with apolar cells, among which only a few are unipolar.Stieda(Centralnervensystem der Vögel, 1868) finds both apolar and unipolar cells in the spinal ganglia of birds.Axmann(De Gangliorum Systematis Structura penitiori, 1847) says the spinal cells are all unipolar.Schwalbe(Archiv für mikros. Anat., 1868) andCourvoisier(ibid., 1869) say the same. So alsoRanvier,Comptes Rendus, 1875.Kölliker(Gewebelehre) speaks decidedly in favor of both apolar and unipolar cells, but thinks the apolar are embryonic.Pagliani(Saggio sullo Stato attuale delle Cognizioni della Fisiologia intorno al Sistema nervoso, 1873), who represents the views ofMoleschott, admits the existence of apolar and unipolar cells. The authors just cited are those I happen to have before me during the rewriting of this chapter, and the list might easily be extended if needful.Auerbach,Bidder, andSchweigger-Seideldescribe unipolar cells which in some places present the aspect of bipolar cells simply because two cells lie together, their single poles having opposite directions. I will add that the bipolar cells do not really render the physiological interpretation a whit more easy than the unipolar, for they are simply cells which form enlargements in the course of the nerve-fibres.
145Auerbach(Ueber einen Plexus Myentericus, 1862) describes the ganglia as filled with apolar cells, among which only a few are unipolar.Stieda(Centralnervensystem der Vögel, 1868) finds both apolar and unipolar cells in the spinal ganglia of birds.Axmann(De Gangliorum Systematis Structura penitiori, 1847) says the spinal cells are all unipolar.Schwalbe(Archiv für mikros. Anat., 1868) andCourvoisier(ibid., 1869) say the same. So alsoRanvier,Comptes Rendus, 1875.Kölliker(Gewebelehre) speaks decidedly in favor of both apolar and unipolar cells, but thinks the apolar are embryonic.Pagliani(Saggio sullo Stato attuale delle Cognizioni della Fisiologia intorno al Sistema nervoso, 1873), who represents the views ofMoleschott, admits the existence of apolar and unipolar cells. The authors just cited are those I happen to have before me during the rewriting of this chapter, and the list might easily be extended if needful.Auerbach,Bidder, andSchweigger-Seideldescribe unipolar cells which in some places present the aspect of bipolar cells simply because two cells lie together, their single poles having opposite directions. I will add that the bipolar cells do not really render the physiological interpretation a whit more easy than the unipolar, for they are simply cells which form enlargements in the course of the nerve-fibres.
146When Dr.Bealesays “that it is probable no nerve-cell exists which has onlyone single fibreconnected with it” (Bioplasm, p. 186), he has no doubt this in his mind; since he would not, I presume, deny that there are cells each with a singleprocess.
146When Dr.Bealesays “that it is probable no nerve-cell exists which has onlyone single fibreconnected with it” (Bioplasm, p. 186), he has no doubt this in his mind; since he would not, I presume, deny that there are cells each with a singleprocess.
147Deiters,Untersuchungen über Gehirn und Rückenmark, 1865.
147Deiters,Untersuchungen über Gehirn und Rückenmark, 1865.
148Archiv für mikros. Anat., 1869, p. 217. Compere alsoButzke,Archiv für Psychiatrie, 1872, p. 584.
148Archiv für mikros. Anat., 1869, p. 217. Compere alsoButzke,Archiv für Psychiatrie, 1872, p. 584.
149Henle,Nervenlehre, 1871, p. 58, Fig. 21.
149Henle,Nervenlehre, 1871, p. 58, Fig. 21.
150When men of such experience and skill asKölliker,Bidder,Goll, andLockhart Clarkedeclare that they have never seen a cell-process pass directly into a dark-bordered fibre in the anterior root, what are we to say to such figures and descriptions as those given in the works ofSchröder van der Kolk,Gratiolet, andLuys? Even did such arrangements exist, no transverse nor longitudinal section could display them, owing to the different planes at which the fibres enter, and the length and irregularity of their course.
150When men of such experience and skill asKölliker,Bidder,Goll, andLockhart Clarkedeclare that they have never seen a cell-process pass directly into a dark-bordered fibre in the anterior root, what are we to say to such figures and descriptions as those given in the works ofSchröder van der Kolk,Gratiolet, andLuys? Even did such arrangements exist, no transverse nor longitudinal section could display them, owing to the different planes at which the fibres enter, and the length and irregularity of their course.
151Long after the text was written,Willigkpublished inVirchow’s Archiv, 1875, LXIV. p. 163, observations of anastomoses which evenKöllikeradmitted to be undeniable. Yet out of sixty-four preparations, amid hundreds of cells, he could only reckon seven cases of conjunction.
151Long after the text was written,Willigkpublished inVirchow’s Archiv, 1875, LXIV. p. 163, observations of anastomoses which evenKöllikeradmitted to be undeniable. Yet out of sixty-four preparations, amid hundreds of cells, he could only reckon seven cases of conjunction.
152See the history given inStilling’slearned work,Ueber den Bau der Nervenprimitiv-Faser, p. 34; and compareMax Shultze,De Retinæ Structura, p. 8, andBau der Nasenschleimhaut, p. 66;Waldeyer, in theZeitschrift für rat. Med., 1863;ListerandTurner,Observations on the Structure of Nerve-Fibres, inQuarterly Micros. Journal, 1859;Ranvier, in theArchives de Physiologie, 1872.
152See the history given inStilling’slearned work,Ueber den Bau der Nervenprimitiv-Faser, p. 34; and compareMax Shultze,De Retinæ Structura, p. 8, andBau der Nasenschleimhaut, p. 66;Waldeyer, in theZeitschrift für rat. Med., 1863;ListerandTurner,Observations on the Structure of Nerve-Fibres, inQuarterly Micros. Journal, 1859;Ranvier, in theArchives de Physiologie, 1872.
153Virchow’s Archiv, Bd. LXXII. p. 193.
153Virchow’s Archiv, Bd. LXXII. p. 193.
154Monthly Journal of Micros. Science, 1874, XI. p. 214.
154Monthly Journal of Micros. Science, 1874, XI. p. 214.
155Babuchin,Centralblatt, 1868, p. 756.
155Babuchin,Centralblatt, 1868, p. 756.
156Even so eminent an authority asW. Krauseholds this both with regard to the varicose aspect and the double contour:Handbuch der menschlichen Anatomie, 1876, I. 367.Butschli, however, describes the nerves in a living Nematode as varicose:Archiv für Anat., 1873, p. 78; and I have somewhere met with an observation of the double contour being visible in the living animal.
156Even so eminent an authority asW. Krauseholds this both with regard to the varicose aspect and the double contour:Handbuch der menschlichen Anatomie, 1876, I. 367.Butschli, however, describes the nerves in a living Nematode as varicose:Archiv für Anat., 1873, p. 78; and I have somewhere met with an observation of the double contour being visible in the living animal.
157Butzke,Archiv für Psychiatrie, 1872, p. 594, states that the granular substance has the chemical composition of myeline. If this be so, we may suppose the “fibrils of crystallization” to represent the coagulation of the substance which is in solution amid the myeline granules, and corresponds with the axis cylinder of a fibre. I may remark that in almost every good preparation nerve-cells will be found in which, while one process is distinctly granular, another is striated or even fibrillated.
157Butzke,Archiv für Psychiatrie, 1872, p. 594, states that the granular substance has the chemical composition of myeline. If this be so, we may suppose the “fibrils of crystallization” to represent the coagulation of the substance which is in solution amid the myeline granules, and corresponds with the axis cylinder of a fibre. I may remark that in almost every good preparation nerve-cells will be found in which, while one process is distinctly granular, another is striated or even fibrillated.
158Boll,Die Histiologie und Histiogenese der nervösen Centralorgane, in theArchiv für Psychiatrie, 1873, p. 47.
158Boll,Die Histiologie und Histiogenese der nervösen Centralorgane, in theArchiv für Psychiatrie, 1873, p. 47.
159Stieda,Studien über das Centralnervensystem der Vögel, 1868, p. 65.Mauthner,Op. cit., p. 4.
159Stieda,Studien über das Centralnervensystem der Vögel, 1868, p. 65.Mauthner,Op. cit., p. 4.
160TurnerandLister,Op. cit., p. 8.
160TurnerandLister,Op. cit., p. 8.
161Blessig,De Retinæ Structura, 1857.
161Blessig,De Retinæ Structura, 1857.
162Luys,Recherches sur le Système nerveux, 1865, p. 267. In a recent and remarkable treatise the student is informed that “plus une cellule est chargée d’un rôle purement mécanique plus elle est volumineuse; plus l’acte qu’elle produit tend à revêtir un caractère psychique plus elle est petite”; to move a limb theagitationof the cerebral cells mustmaterialize itselfmore and more, “Il a besoin de passer par des cellules, de moins en moins spirituelles et de plus en plus matérielles.... De même pour les cellules sensitives. L’impression extérieure va en se modifiant, en se spiritualisant, de la périphérie au centre.... Un phénomène de l’ordre spirituel ne sanrait devenir sans transition un phénomène d’ordre physique.” And what is this marvellous transition between spiritual and physical? It is the action of medium-sized cells which “travaillent la vibration reçue, la modifient de façon à lui ôter de son spiritualisme et à la rapprocher davantage des ébranlements physiques.” I will not name the estimable author, because he is simply restating what many others implicitly or explicitly teach; but I will only ask the reader to try and realize in thought the process thus described.
162Luys,Recherches sur le Système nerveux, 1865, p. 267. In a recent and remarkable treatise the student is informed that “plus une cellule est chargée d’un rôle purement mécanique plus elle est volumineuse; plus l’acte qu’elle produit tend à revêtir un caractère psychique plus elle est petite”; to move a limb theagitationof the cerebral cells mustmaterialize itselfmore and more, “Il a besoin de passer par des cellules, de moins en moins spirituelles et de plus en plus matérielles.... De même pour les cellules sensitives. L’impression extérieure va en se modifiant, en se spiritualisant, de la périphérie au centre.... Un phénomène de l’ordre spirituel ne sanrait devenir sans transition un phénomène d’ordre physique.” And what is this marvellous transition between spiritual and physical? It is the action of medium-sized cells which “travaillent la vibration reçue, la modifient de façon à lui ôter de son spiritualisme et à la rapprocher davantage des ébranlements physiques.” I will not name the estimable author, because he is simply restating what many others implicitly or explicitly teach; but I will only ask the reader to try and realize in thought the process thus described.
163Schröder Van Der Kolk,Pathologie der Geisteskrankheiten, 1863, p. 69.
163Schröder Van Der Kolk,Pathologie der Geisteskrankheiten, 1863, p. 69.
164Wundt,Physiologische Psychologie, p. 261. In hisMechanik der Nerven, 2 Abth.(published just as this sheet is going to press), he shows that a stimulus is both retarded and weakened in its passage through a ganglion.
164Wundt,Physiologische Psychologie, p. 261. In hisMechanik der Nerven, 2 Abth.(published just as this sheet is going to press), he shows that a stimulus is both retarded and weakened in its passage through a ganglion.
165Trinchesealso says that the fibres “provengono dalle cellule enon son altro che i loro prolungamenti o poli.”—Op. cit., p. 13. An unequivocal example is seen in theTorpedo, where the large cells have each their prolongation continuing without interruption into the electrical organ. See the figure given byReichenheimin theArchiv für Anat., 1873, Heft VI.
165Trinchesealso says that the fibres “provengono dalle cellule enon son altro che i loro prolungamenti o poli.”—Op. cit., p. 13. An unequivocal example is seen in theTorpedo, where the large cells have each their prolongation continuing without interruption into the electrical organ. See the figure given byReichenheimin theArchiv für Anat., 1873, Heft VI.
166Golgi,Sulla struttura della sostanza grizia del Cervello.Arndt,Archiv für mikros. Anat.1870, p. 176.Rindfleischalso traces these processes into the neuroglia (ibid., 1872, p. 453). “Deiters, Boddaert, and other observers have stated that one dark-bordered nerve-fibre enters each cell.... My own observations lead me to conclude thatallthe fibres are composed of the same material, but that one fibre does not divide until it has passed some distance from the cell, while others give off branches much closer to it.”—Beale,Bioplasm, p. 189.
166Golgi,Sulla struttura della sostanza grizia del Cervello.Arndt,Archiv für mikros. Anat.1870, p. 176.Rindfleischalso traces these processes into the neuroglia (ibid., 1872, p. 453). “Deiters, Boddaert, and other observers have stated that one dark-bordered nerve-fibre enters each cell.... My own observations lead me to conclude thatallthe fibres are composed of the same material, but that one fibre does not divide until it has passed some distance from the cell, while others give off branches much closer to it.”—Beale,Bioplasm, p. 189.