85The development of the olfactory lobe and bulb is similar; it need not be followed here.

86German anatomists divide this axis into trunk and crown (Hirnstamm and Hirnmantel). 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 the crown, and leave the trunk remaining. 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, Bernard is 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 of Sigmund 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, see Problems: First Series, Vol. II. p. 159

91I do not here touch upon the question as to whether these actions of the senses are sensations, because that question demands that we should first settle what is Sensation. I may at once, however, say that what is ordinarily understood as a sensation of color, or a sensation of sound, 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.

93Owsjannikow describes the results of removing carefully the cranial ganglia of the crayfish; and these effects Meyer observes 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. Faivre as following the destruction of one suboesophageal ganglion in the Dytiscus, 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, and Physiology of Common Life, 1860.

This recognition of sensation, and even of volition, in spinal actions may be found in the writings of Whytt, Unzer, Prochaska, Legallois, and Mayo; but the establishment of the Reflex Theory had displaced it, and its revival dates from PflÜger.

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 the Physiology 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 de neurilitÉ; 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 also Gavarret, 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 of Haller, Sur la nature sensible et irritable des parties, I. 245; and the remarks of Prochaska, De Functionibus Systematis Nervosi (translated by Laycock in the volume published by the Sydenham 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, in Journal of Anatomy, 1873, No. VIII. p. 331. (Fleischl denies that the nerve in situ has different degrees of reaction. Sitzungsberichte der Wiener Akad., December, 1876.)

103Munk, in the Archiv 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 of La 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. Fick expressed 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 SÉquard tries to establish a distinct species of nerves as conductors of sensitive impressions, from those which are impressionable. 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; and Lectures in the Lancet, 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 is set; it cannot vary the performance,—cannot play a false note, or throw in a crescendo here, a largo there, 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 truth incorporate them. 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 Foster and Mr. Dew Smith have 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.

Donders has 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 in PflÜger’s Archiv, Bde. II. and IV.

121D’Orbigny, Des Mollusques VÍvants et fossils, p. 113.

122Seaside Studies, 2d ed., p. 101.

123Cited by Brown SÉquard, Journal de la Physiologie, 1858, p. 359.

124Dr. Norris has recorded some striking observations in his paper on “Muscular Irritability” in the Journal of Anatomy, 1867, No. II. p. 217. Here is the only one I can find room for: “On taking up the dead frog 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 two apparently spontaneous movements of 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 the Archiv 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 the Psychological Spectrum.

127Foster and Balfour, 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 of Kowalewsky are 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 to Balfour’s recent 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 recently Owsjannikow has pointed out the termination of fibres in the phosphorescent cells of the Lampyris Noctiluca. See his paper in the MÉmoires de l’Acad. de St. Petersbourg, 1868, XI. 17. These phosphorescent cells are said to be ganglion-cells by Panceri, Intorno della luce che emana dalle celleule nervose (Rendiconto della Accad. delle Scienze, April, 1872); and by Eimer, Archiv fÜr mikros. Anatomie, 1872, p. 653. KÖlliker also 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.

133Bidder und Kupffer, 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 of Charles 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. Allman in the Myriothela; 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. Gegenbaur declares his inability to decide whether these processes are muscles or nerves. BÜtschli thinks 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,” says KÖlliker, “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 to 3 ( = 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 of Heitzmann be confirmed, there would be ground for believing that neurine is normally fibrillated. He says that the living protoplasm in the Amoeba, white blood-corpuscle, etc., is an excessively fine network, which condenses into granules at each contraction. (Cited in the Jahresberichte 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 to Mauthner, 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 it impossible for 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.”

144Eichhorst in Virchow’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) and Courvoisier (ibid., 1869) say the same. So also Ranvier, 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 of Moleschott, 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, and Schweigger-Seidel describe 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. Beale says “that it is probable no nerve-cell exists which has only one single fibre connected 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 single process.

147Deiters, Untersuchungen Über Gehirn und RÜckenmark, 1865.

148Archiv fÜr mikros. Anat., 1869, p. 217. Compere also Butzke, Archiv fÜr Psychiatrie, 1872, p. 584.

149Henle, Nervenlehre, 1871, p. 58, Fig.21.

150When men of such experience and skill as KÖlliker, Bidder, Goll, and Lockhart Clarke declare 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 of SchrÖder van der Kolk, Gratiolet, and Luys? 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, Willigk published in Virchow’s Archiv, 1875, LXIV. p. 163, observations of anastomoses which even KÖlliker admitted 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 in Stilling’s learned work, Ueber den Bau der Nervenprimitiv-Faser, p. 34; and compare Max Shultze, De RetinÆ Structura, p. 8, and Bau der Nasenschleimhaut, p. 66; Waldeyer, in the Zeitschrift fÜr rat. Med., 1863; Lister and Turner, Observations on the Structure of Nerve-Fibres, in Quarterly Micros. Journal, 1859; Ranvier, in the Archives 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 as W. Krause holds 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 the Archiv fÜr Psychiatrie, 1873, p. 47.

159Stieda, Studien Über das Centralnervensystem der VÖgel, 1868, p. 65. Mauthner, Op. cit., p. 4.

160Turner and Lister, 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 the agitation of the cerebral cells must materialize itself more 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 his Mechanik 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.

166Golgi, Sulla struttura della sostanza grizia del Cervello. Arndt, Archiv fÜr mikros. Anat. 1870, p. 176. Rindfleisch also 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 that all the 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.

167Beale, Bioplasm, p. 177. Max Schultze, in Stricker’s Handbuch, p. 134. Comp. Stilling, Nervenprimitiv-Faser, p. 133. Arndt, Archiv fÜr mikros. Anat., 1868, p. 512; and 1869, p. 237. Weighty as these authorities are, their view is questionable—firstly, because the forms of these cells are too constant and definite in particular places to result from the union of fibrils coming from various origins; but secondly, and mainly, because the teaching of Development is opposed to it.

168Robin, Anat. et Physiol. Cellulaires, p. 335.

169Archives de Physiologie, 1872, p. 268.

170The fact of the existence of cells in the white substance is one which is very difficult of interpretation on the current hypotheses. The cells are found in regular columns and irregularly scattered. Boll thinks that while in the white substance of both cerebrum and cerebellum there are true nerve-cells as well as connective corpuscles, in the cord there are only the latter. But hitherto there has been no decisive test by which a nerve-cell can be distinguished from a connective corpuscle.

171Monthly Journal of Micros. Science, XI. 219. This accords with what Kupffer says respecting the entire absence of cells in the earliest stages observed by him in the sheep. The white substance of the spinal cord he describes as soft, transparent, and gelatinous, in which dark points are visible; these dark points are seen in longitudinal sections to arise from the fibrillation of the substance.—Bidder und Kupffer, Op. cit., p. 111.

172Weismann, Die nachembryonale Entwick. der Musciden, in the Zeitschrift fÜr Wissen. Zoologie, 1864, Bd. XIV. Heft III.

173The suggestion in the text has since received a striking confirmation in the observations of Sigmund Mayer on the regeneration of nerves. The nerve when divided rapidly undergoes fatty degeneration, which is succeeded by a transformation of the myeline and axis cylinder into a homogeneous mass; in this resolved pulp new longitudinal lines of division appear, which subsequently become new fibres, and new nuclei are developed in the remains of the untransformed substance.—Archiv fÜr Psychiatrie, Bd. VI. Heft II.

174Strong confirmation of various statements in the text, since they were written, has been furnished by the researches of Eichhorst, published in Virchow’s Archiv, LXIV. Our knowledge of the development of nerve-tissue in human embryos is so scanty that these researches have a great value. Eichhorst describes the striation of the cells in the cord to begin only at the fourth month; up to this time they are, what I find most invertebrate cells to be, granular, not fibrillar. There is very slight branching of the cell processes until the ninth or tenth month, when the multipolar aspect first appears; the cells are unipolar up to the end of the fourth month. The connection between the white columns and the gray columns is very loose up to the fifth month; and the two are easily separated. Subsequently the union is closer. The substance of the white columns readily separates into bundles and fibres, but that of the gray columns falls into a granular detritus if attempted to be teased out with needles. But after the fifth month this is no longer so. Instead of a granular detritus there appears a network of fine fibres and fibrils. Although the white posterior columns are developed before the fifth month, not a single cell can be seen in the posterior gray columns until the second half of the ninth month. (Yet the fibres are imagined to arise in the cells!) The passage from the granular to the fibrillar state is the same in the cell substance and the neuroglia. The nerve-fibre, as distinguished from a naked axis cylinder, does not appear till the fourth month. It is at first a bipolar prolongation of the nucleus. As it elongates, the nucleus seems to sit on it, and so loosely that it is easily shifted away by pressure on the covering glass. Finally the fibre separates entirely from the nucleus, and then begins to clothe itself with the medullary sheath. Very curious is the observation that so long as the axis cylinder is naked it is never varicose, but with the development of the medulla the primitive axis becomes fluid.

175Mayer, Op. cit., 393. I cannot, however, agree with Mayer when he says that the continuity of a nerve-fibre with a cell has never been distinctly shown (p. 395); in the Invertebrata and in the Electric fishes such a continuity is undeniable; and it has occasionally been seen in Vertebrata.

176Ranvier, in the Comptes Rendus, 1875, Vol. LXXXI. p. 1276. This observation throws light on the fact that cell processes are sometimes seen entering nerve-roots (§124).

The very remarkable observations of Mr. F. Balfour, On the Development of the Spinal Nerves in Elasmobranch Fishes (Philos. Trans., Vol. CLXVI. p. 1), show that the spinal root, ganglion, and nerve-trunk arise from histological changes in a mass of cells at first all alike; not that ganglion-cells are formed and from their processes elongate into fibres. The nerve, he says, forms a continuation of its root rather than of its ganglion (p. 181); which accords with Ranvier’s view.

177In the Handbuch der menschlichen Anatomie of W. Krause, which has just appeared, I am pleased to find a similar view, p. 376.

178On this point consult Axel Key and Retzius, in the Archiv fÜr mikros. Anat., 1873, p. 308, where the nutritive disturbance is assigned to the fact that the lymph can no longer take its normal course. Waller’s observations on the degeneration of the optic nerves, with preservation of the integrity of the retina, after division of the nerves (Proceedings of Royal Society, 1856, p. 10), cannot be urged in support of his view, because Berlin and Lebert’s observations are directly contradictory of his. Saemisch und Graefe, Handbuch der Augenheilkunde, II. 346. It is said by Krenchel that if the nerves be divided, so as to prevent disturbances in the circulation, no peripheral degeneration takes place (cited by Engelmann in PflÜger’s Archiv, 1875, p. 477).

179Schiff, Lehrbuch der Physiologie, pp. 120, 121.

180KÖlliker, Gewebelehre, 317. Schwalbe, Archiv fÜr mikros. Anat., 1868, p. 51.

181I was first shown this in 1858 by the late Prof. Harless in Munich, who at the same time showed me that the nerve thus bared of its sheath, if left some hours in gastric juice, split up into regular discs, like the sarcous elements of muscles.

182Stieda, Bau des centralen Nervensystem der Amphibien und Reptilien, 1875, p. 41.

183Butzke, in Archiv fÜr mikroskopische Anatomie, Bd. III. Heft 3, p. 596.

184Except in the rare cases where there is anastomosis of the muscle-fibres; as, for example, in the heart. [According to Engelmann’s remarkable researches, the muscles of the heart form a continuum, so that irritation is propagated from one to the other: PflÜger’s Archiv, 1875, p. 465. This is indubitably the case in the embryonic heart, as Eckhard pointed out.] This I hold to be the main cause of its rhythmic pulsation after removal from the body. Whatever influence the ganglia may have in exciting this pulsation, such influence would be powerless were not the muscles so connected; as may be seen in the other organs which are richly supplied with ganglia, yet do not move spontaneously; and in organs (such as the ureter or the embryonic heart, and the hearts of invertebrata) which move spontaneously, yet have no ganglia.

185SchrÖder van der Kolk, Bau und Funktionen der Med. Spinalis, p. 67.

186It is very instructive to learn that for some six months or so the rat is quite incapable of correctly localizing the pain.

187Vulpian, LeÇons sur le SystÈme Nerveux, p. 288. The experiment has been confirmed by Rosenthal, and by Bidder (Archiv fÜr Anatomie, 1865, p. 246), who first (in 1842) attempted this union of different nerves, but arrived at negative results; as did Schiff (Lehrbuch der Physiol, 1859, p. 134) and Gluge et Thiernesse (Annales des Sciences Naturelles, 1859, p. 181).

188Sachs, in the Archiv fÜr Anat., 1874, pp. 195, sq.

189Laplace, Essai Philos. sur les ProbabilitÉs, p. 239.

190The mode of termination of nerves in muscles is still a point on which histologists disagree; probably because there is no abrupt termination, but a blending of the one tissue with the other. In the Tardigrades, for example, there is actually no appreciable distinction between nerve and muscle at the point of insertion of the nerve; and if in the higher animals there is an appreciable difference between nerve and muscle, there is an inseparable blending of undifferentiated substance at their point of junction. [According to Engelmann’s recent researches, there seems good reason to suppose that muscles are composed of contractile substance and a substance which is a modification of axis-cylinder substance; the first being doubly refracting, the second isotropic: PflÜger’s Archiv, 1875, p. 432.]

191Schiff, Lehrbuch, p. 73.

192Freusberg observed that the reflex movements in the legs of a dog whose spine had been divided were considerably lessened after food or drink. They fell from 95 to 46 pendulum-beats in a minute after a litre of water had been drunk. See his instructive memoir, Reflex-LÄhmungen beim Hunde, in PflÜger’s Archiv, 1874, p. 369.

193M. Herzen thus describes the effects of stimulating the vagus with varying intensities: “Si l’on se sert de l’appareil de Dubois Raymond, on commence par appliquer une irritation tellement faible qu’elle ne produit aucun effet; on rapproche alors peu À peu lea deux bobines de l’appareil avec le plus grand soin, par fractions de centimÈtres, par millimÈtres s’il le faut, et l’on trouve ainsi le degrÉ d’irritation qui accelÈre les battements du coeur et qui produit le maximum de pulsations dans l’unitÉ de temps admise pour l’expÉrience. Quand on est lÀ il suffit d’un millimÈtre de plus pour faire disparaÎtre l’augmentation, un autre millimÈtre peut produire une diminution, et un troisiÈme peut arrÊter le coeur complÈtement. En reculant alors, en Éloignant peu À peu les deux bobines, on rÈtourne À la force qui produit l’augmentation des battements.” Herzen, ExpÉriences sur les Centres ModÉrateurs de l’Action RÉflexe, 1864, p. 68. There have been serious doubts thrown on these experiments; but several experimenters have confirmed their exactness. Quite recently they have been confirmed by Bulgheri, Il Morgagni, VIII.; and by Arloing and Tripier, Archives de Physiologie, 1872, IV. p. 418. It must be confessed, however, that the whole subject of the heart’s innervation is at present very imperfectly understood.

194Cayrade, Recherches sur les Mouvements RÉflexes, 1864, p. 58.

195A frog’s brain is removed, and the body then suspended by the lower jaw, the legs are allowed to dip into a slightly acidulated liquid, the chemical action of which stimulates the skin.

196I saw a patient in the Berlin CharitÉ whose face and left hand were in a constant state of convulsive twitching, but no sooner was a scar on the left hand (where the nerve had been divided) firmly pressed than the twitchings ceased, and pain was felt; on removal of the pressure, pain ceased and the twitchings returned.

197PflÜger’s Archiv, 1875. No one interested in the Reflex Theory should omit a careful study of the papers by Freusberg and Goltz. I have drawn freely from them.

198Sir James Paget has an interesting collection of facts which illustrate this Law of Arrest, in his paper on “Stammering with other Organs than those of Speech,” British Medical Journal, 1868, Vol. II. p. 437, reprinted in his Clinical Lectures and Essays, 1875, p. 77.

199Archives de Physiol., 1868, p. 157.

200West Riding Lunatic Asylum Reports, 1874, p. 200.

201Claude Bernard, SystÈme Nerveux, I. 383.

202See the excellent remarks of Dr. Lauder Brunton on this point in his paper on Inhibition in the West Riding Lunatic Asylum Reports, 1874, p. 180.

203The interesting question of interference has been experimentally treated by Wundt in his recently published Mechanik der Nerven, 1876, and theoretically as wave-movement by Medem, GrundzÜge einer exakten Psychologie, 1876.

204On the distinction between first notions and theoretic conceptions, see Problems of Life and Mind, Vol. II. p. 277.

205Not transcendental and a priori, as Kant teaches; but immanent in Feeling.

206The reader will understand that although mechanical relations are modes of Feeling, as all other relations are, yet their aspect is exclusively objective, referring to objects ideally detached from subjects.

207Antoine Cros, Les Fonctions supÉrieures du SystÈme nerveux, 1875, p. 85.

208The solution offered in the present chapter was first offered in Problems of Life and Mind, 1875, II. 465, sq. I mention this because since the publication of that volume other writers have expressed the same ideas, sometimes using my language and illustrations: e.g. M. Taine in the Revue Philosophique, January, 1877, art., Les Vibrations cÉrÉbrales et la PensÉe.

209Problems of Life and Mind, Vol. II. pp. 443 and 482.

210“The retinal image is the last effect known of the action of objects on us; what happens beyond the retina we know not; our knowledge of the objective process has at present here its limit.”—Ewald Hering, BeitrÄge zur Physiologie, 1862, p. 166. That is to say, we have a definite translation of the process in geometric terms as far as the retina, and thence onwards Geometry fails us, and Neurology and Psychology are invoked.

211Compare Problem II. Chap. IV.

212“Das Bewusstwerden ist nichts Anderes als ein weiter fortgeschrittenes Erinnern oder Neuwerden des von aussen aufgenommenen Wissens, ein innerliches Wissen dieses Wissens oder ein in sich reflectirtes Wissen.”—Jessen, Versuch einer Wissenschaftlichen BegrÜndung der Psychologie, 1855, p. 477.

213In common language a stone or a tree is said to be unconscious; but this is an anthropomorphic extension of the term. In strictness we should no more speak of unconsciousness outside the sphere of Sentience than of darkness outside the sphere of Vision.

214The contraction may be effected in the eye out of the organism. See p. 229. It is then no reflex.

215Glasgow Medical Journal, 1857, p. 451. See also further on, note to p. 426.

216Mayer, Die Elementarorganisation des Seelenorgans, p. 12, is the authority for the last statement.

217Allgemeine Zeitschrift fÜr Psychiatrie, Bd. 31, p. 711.

218Aubert, GrundrÜge der physiol. Optik, 1876, p. 633. “The accommodative movement of the eye is to be considered voluntary. It is true we contract the pupil without being conscious of the contraction of muscular fibres, but this holds good for every voluntary movement. When a person raises the tone of his voice he is not conscious that by muscular contraction he makes his chordÆ vocales more tense; he attains his object without being aware of the means by which he does so. The same is applicable to accommodation for near objects and to the contraction of the pupil accompanying it. The fact that this last is only an associated movement does not deprive it of its voluntary character, for there is perhaps no single muscle which can contract entirely by itself.” Donders, On the Anomalies of Accommodation, 1864, p. 574. Professor Beer of Bonn has the rare power of contracting or dilating the pupils of his eye at will; here ideas act as motors. When he thinks of a very dark space the pupil dilates, when of a very bright spot the pupil contracts. (Noble, The Human Mind, 1858, p. 124.) I believe this to be only an exaggerated form of the normal tendency. In all of us the mechanism is so disposed that the feelings of dilatation are associated with feelings (and consequently ideas) of darkness; and by this association a reversal of the process obtains, so that the idea of darkness calls up the feeling it symbolizes.

219Spencer, Principles of Psychology, I. 499.

220Descartes expressly calls them sensitive machines. He refuses them Thought, but neither “la vie ou le sentiment.” He adds, “Mon opinion n’est pas que les bÊtes voient comme nous lorsque nous sentons que nous voyons.”—Œuvres, IV. p. 339. This example is cited by him in proof of human automatism: “Que ce n’est point par l’entremise de notre Âme que les yeux se ferment, puisque c’est contre notre volontÉ, laquelle est sa seule ou du moins sa principale action; mais c’est À cause que la machine de notre corps est tellement composÉe que le mouvement de cette main vers nos yeux excite un autre mouvement en notre cerveau qui conduit les esprits animaux dans les muscles qui font abaisser les paupiÈres.” All indeed that we assign to Sensibility, he assigns to these hypothetical animal spirits, and thence he concludes, “Qu’il ne reste rien en nous que nous devions attribuer À notre Âme sinon nos pensÉes.”—Les Passions de l’Âme, art. 13 and 17. Comp. Discours de la MÉthode, partie iv.

221Descartes compares the animal mechanism to that of the grottos and fountains at Versailles, the nerves to the water-tubes:—“Les objets extÉrieurs qui par leur seul prÉsence, agissent contre les organes des sens, et qui par ce moyen, la dÉterminent À se mouvoir en plusieurs diverses faÇons, selon comme les parties du cerveau sont disposÉes, sont comme les Étrangers, qui entrant dans quelques unes des grottes de ces fontaines causent euxmÊmes sans y penser les mouvements qui s’y font en leur prÉsence: car ils n’y peuvent entrer qu’en marchant sur certains carreaux tellement disposÉs, que s’ils approchent d’une Diane qui se baigne, ils la font cacher dans les roseaux; et s’ils passent outre pour la poursuivre, ils feront venir vers eux un Neptune qui les menacera de son trident; ou s’ils vont de quelque autre costÉ, ils en feront sortir un monstre marin qui leur vomira de l’eau contre la face.”—TraitÉ de l’Homme, 1664, p. 12. Ingenious as the comparison is, it only illustrates how machines may be constructed to imitate animal actions. Diana always hides herself when a certain spot is trodden upon; and Neptune always appears when another spot is trodden upon. There is no fluctuation, no sensibility discerning differences and determining variations. Compare the following experiment: A monkey was placed on the table and a shrill whistle made close to its ear: “Immediately the ear was pricked and the animal turned with an air of intense surprise, with eyes widely opened and pupils dilated, to the direction whence the sound proceeded. On repetition of the experiment several times, though the pricking of the ear and the turning of the head and eyes constantly occurred, the look of surprise and dilatation of the pupils ceased to be manifested.”—Ferrier, The Functions of the Brain, 1876, p. 171. A mechanical monkey would always have reacted in precisely the same way on each stimulus.

222Printed in the Fortnightly Review, November, 1874, from which all my citations are made.

223Schiff, Lehrbuch der Physiol., 1858, p. 212. Hermann, Physiology, translated by Gamgee, 1875, p. 511.

224Meanwhile the reader is referred to SchrÖder van der Kolk, Pathologie der Geisteskrankheiten, 1863, p. 51; or Jessen, Physiologie des menschlichen Denkens, 1872, p. 66.

225Griesinger, Les Maladies Mentales, p. 96.

226M. Luys cites the case of a patient who conversed quite rationally with a visitor “sans en avoir conscience, et ne se souvenait de rien”; and he draws the extraordinary conclusion that the conversation “s’opÉrait en vertu des forces rÉflexes.”—Études de Physiologie et de Pathologie CÉrÉbrales, 1874, p. 117. Is it not obvious that the patient must have been conscious at the time, though the consciousness vanished like that in a dream? The persistent consciousness is the continuous linking on of one state with previous states—the apperception of the past.

227Abercrombie, Inquiries concerning the Intellectual Powers, 1840, p. 151. Wigan, The Duality of the Mind, 1844, p. 270. Despine, La Psychologie Naturelle, 1868, I. 54.

228Dr. Hughlings Jackson has quite recently cited some curious examples in his own practice. See West Riding Lunatic Asylum Reports for 1875.

229Problems, Vol. II. p. 478, sq.

230“Le sentiment fait naÎtre le mouvement, et le mouvement donne naissance au sentiment.”—Van Deen, TraitÉs et DÉcouvertes sur la MoËlle ÉpiniÈre, 1841, p. 102.

231Dr. Carpenter tells a similar story of Admiral Codrington, who, when a midshipman, could always be awakened from the profoundest slumber if the word “signal” were uttered; whereas no other word disturbed him.

232Compare an interesting personal example given by Jouffroy, quoted in Sir W. Hamilton’s Lectures, I. 331.

233Lancet, 10th July, 1858.

234Marshall Hall in Philos. Trans., 1833. Lectures on the Nervous System and its Diseases, 1836. New Memoir on the Nervous System, 1843.

235MÜller, Physiology, I. 721.

236It is better simply to remove the brain, than to remove the whole head, which causes a serious loss of blood. An etherized animal may be operated on with ease and accuracy. For many experiments, mere division of the spinal cord is better than decapitation. Great variations in the results must be expected, because the condition of the animal, its age and sex—whether fasting or digesting—whether the season be spring or summer—and a hundred other causes, complicate the experiment.

237Volkmann, quoted by PflÜger.

238Unzer, The Principles of Physiology (translated for the Sydenham Society), p. 235.

239Even so eminent an investigator as Goltz has fallen into this confusion. He introduces an experiment to prove that the brainless frog is insensible to pain by the words “when an animal, placed under circumstances which would be very painful, makes no movement, although quite capable of moving, the least we can say is that it is improbable that the animal has sensation” (Nervencentren des Frosches, p. 127). I need not discuss the proof itself, having already done so in Nature, Vol. IX. p. 84. The point to which I wish to call attention is the confusion of insensibility in general with insensibility to pain.

240See Duchenne, De Électrisation localisÉe, p. 398. Griesinger cites various examples of insane patients who have burned the flesh off their bones while manifesting a total indifference to these injuries. Maladies Mentales, p. 94. Falret says, “Nous avons vu plusieurs fois des aliÉnÉs s’inciser, s’amputer eux-mÊmes diverses parties du corps sans paraÎtre ressentir aucune souffrance.” LeÇons cliniques de MÉdicine Mentale, 1854, I. 189. Patients incapable of feeling the contact of a hot iron with their skin have felt subjective burnings in the skin thus objectively insensible.

241Cros, Les Fonctions supÉrieures du Syst. nerveux, 1875, p. 27.

242Virchow’s Archiv, Bd. XXVIII. p. 30.

243The idea of a fixed anatomical mechanism for reflexion, such as that of an excito-motory system, is completely refuted by the fact that the gray substance may anywhere be cut sway, and yet so long as a small bridge of gray substance remains the stimulation will be propagated through it. The idea of a fixed pathway is also refuted by the fact of the variations in the reflex responses, and the necessary irradiation even for very simple reflexes. Take, for example, that of breathing. An irritation of the bronchial filaments is transmitted by the pneumogastric to its centre in the medulla oblongata; from this, however, it is immediately irradiated downwards to the cervical and dorsal regions, which innervate the muscles of chest and diaphragm, and upwards to the brain, whether the stimulation awaken consciousness or not. One may say, indeed, that inasmuch as under normal conditions the bronchial irritation always causes a movement of a particular group of muscles, there is to this extent a fixed pathway of discharge; but, as I have formerly explained, this is only an expression of the particular tension of particular centres, and is variable with that tension; the other centres are also affected, even when they are not excited to discharge.

244Lallemand, Recherches sur L’EncÉphale, III. 310.

245West Riding Lunatic Asylum Reports, 1875, Vol. V. pp. 252, sq.

246Gall et Spurzheim, Anat. et Physiol. du SystÈme Nerveux, I. 83.

247Printed in the British and Foreign Medical Review, Jan. 1845.

248Griesinger, Abhandlungen, 1872. The first volume contains a reprint of this memoir.

249Landry, TraitÉ des Paralysies, I. 55. Conf. Ziemssen, Chorea in the Handbuch der speciellen Pathologie, Bd. XII. 2, p. 408. And Luys, Études de physiol. et pathol. cÉrÉbrales, 1874, pp. 89–94.

250Sue, Recherches Philosophiques sur la VitalitÉ et le Galvanisme, p. 9. He was not consistent, however, but adopted Bichat’s opinion respecting the sensibility of the viscera, p. 68.

251Legallois, ExpÉriences sur le principe de la vie. Published, I conclude, in 1811; the edition I use is the one printed in the EncyclopÉdie des Sciences Medicales, IV.

253Longet, TraitÉ de Physiologie, II. 105.

254He cites Cuvier, Majendie, Deamoulins, and Mayo as maintaining this error.

255Grainger, Structure and Functions of the Spinal Cord, p. 66.

256Nasse, Unters. zur Physiologie und Pathologie, Vol. II. Part 2.

257Carus, System der Physiologie, III. 101.

258J. W. Arnold, Die Lehre von der Reflex-Function, 86.

259PflÜger, Die sensorischen Functionen des RÜckenmarks der Wirbelthiere.

260Except Auerbach, who repeated and varied the experiments; and Funke, who partially adopted the conclusions in his systematic treatise on Physiology.

261Schiff, Lehrbuch der Physiologie, 208.

262Landry, TraitÉ des Paralysies, 1859, maintains that the cord is a centre of sensation, and that there is in it a faculty analogous to the perception and judgment of the brain. Compare pp. 163 et sq. and 305. He also cites an essay by Dr. Paton of Edinburgh (Edinburgh Medical Journal, 1846), in which the sensational and volitional claims of the spinal cord are advanced.

263Goltz, BeitrÄge zur Lehre von den Functionen der Nervencentren des Froeches, 1869.

264PflÜger’s Archiv, Bd. XIV. p. 158.

265See Prob. II. § 183.

266“Il y a donc une mÉmoire par le cerveau et une mÉmoire par l’automate. Tous les organes ont une mÉmoire propre, c’est À dire une tendance À reproduire les sÉries d’actes qu’ils ont plusieurs fois executÉs.”—Gratiolet, Anat. du SystÈme Nerveux, 1857, p. 464.

267To obviate misunderstanding let me say that, unless the contrary is specified, I use the term Brain throughout this argument as equivalent to the cerebral hemispheres, because it is in these that sensation, volition, and consciousness are localized by the generality of writers, many of whom, indeed, regard the cells of the gray matter of the convolutions as the exclusive seat of these phenomena, dividing these cells into sensational, emotional, and intellectual. There are physiologists who extend sensation to the cerebral ganglia and gray masses of the medulla oblongata; but the medulla spinalis is so clearly continuous with the medulla oblongata that there is a glaring inconsistency in excluding sensation from the one if it is accorded to the other; and the grounds on which sensitive phenomena are admitted in the absence of the hemispheres, force us to admit analogous phenomena in the absence of the ganglia and medulla oblongata: in each case the phenomena are less complex and varied as the mechanisms become less complex.

268Compare Lussana e Lemoigne, Fisiologia dei centri encefalici, 1871, II. 239, 240, 330.

269See a very interesting case of this special loss of memory in a priest who still occupied himself reading classic authors and performing his official duties many months after an injury to the brain. Lussana e Lemoigne, Fisiologia dei centri encefalici, I. 201.

270Bouillaud, Recherches ExpÉrimentales sur les Fonctions du Cerveau en gÉnÉral, 1830, p. 5, sq.

271Longet, TraitÉ de Physiologie, II. 240.

272Dalton, Human Physiology, Philadelphia, 1859, p. 362.

273Dalton, p. 362.

274Dalton, p. 363.

275Flourens, p. 89.

276Leyden in the Berliner klinische Wochenschrift, 1867, No. 7. Meissner, Jahresbericht Über Physiol., 1867, p. 410.

277Voit in the Sitzungsberichte der MÜnchener Academie, 1868, p. 105. Comp. also Goltz in PflÜger’s Archiv, Bd. XIV. 435.

278Vulpian, SystÈme Nerveux, 542–48.

279For other examples see Gintrac, Pathologie Interne, 1868, VI. 51–57.

280If the water is perfectly still the fish sinks to the bottom and remains motionless until the water be stirred. Mere contact does not suffice; there must be intermittent pulses from the moving water.

281Lussana e Lemoigne, Op. cit., I. 15.

282Archives de Physiologie, 1869, p. 539.

283BrÜcke, Physiologie, II. p. 53. While these sheets are passing through the press, Goltz has published his second series of experiments on the brain. The following detail is a good illustration of what is said in the text: A dog deprived of a portion of both hemispheres displayed a marked imperfection in the execution of ordinary instincts. Although sight was impaired he could see, and recognize men and certain objects: the sight of a whip made him cower, but the sight of meat did not suffice to set the feeding mechanism in action. When meat was suspended above his head, the scent caused him to sniff about in search, but he failed to find it, and even when he was so placed that he could see the suspended meat, the unusual impression failed to guide him. If the meat were held towards him, or placed before him in a dish, he took it at once—this being the customary stimulation. So also, if the hand were held up, in the usual way when dogs are made to leap for food, this dog sprang vigorously up and caught the food; but he would spring up in the same way when the hand was held empty, and continue fruitlessly springing, whereas an uninjured dog ceases to spring when he sees the hand is empty.—PflÜger’s Archiv, Bd. XIV. p. 419.

284Gratiolet, Anat. ComparÉe du SystÈme Nerveux, 1857, p. 459.

285Lussana e Lemoigne, Op. cit., I. 363.

286Virchow’s Archiv, Bd. LX. pp. 130–33. Yet there are many physiologists who persist in placing the motorium commune in the corpora strata! And they place the sensorium commune in the optic thalami, although, not to mention the ambiguous evidence of Pathology, the experiments of Nothengel and VeyssiÈre show that destruction of the thalami does not destroy sensation. See VeyssiÈre, Recherches sur l’hÉmianesthÉsie de cause cÉrÉbrale, 1874, pp. 83, 84. I may observe, in passing, that the notion of the corpora striata being the necessary channel for volitional impulses, and the optic thalami for reflex actions, is utterly disproved by the experimental evidence recorded in the text, as well as in §66.

287PflÜger’s Archiv, Bde. VIII. and IX.