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THE RELATIONS OF THE ORGANITES.

133. In enumerating among the obstacles to research the tendency to substitute hypothetic deductions in place of objective facts, I had specially in my mind the widereaching influence of the reigning theories of the nervecell. Had we a solidly established theory of the cell, equivalent, say, to our theory of gas-pressure, we should still need caution in allowing it to override exact observation; but insecure as our data are, and hypothetical as are the inferences respecting the part played by the cell, the reliance placed on deductions from such premises is nothing less than superstition. Science will take a new start when the whole question is reinvestigated on a preliminary setting aside of all that has been precipitately accepted respecting the office of the cell. This exercise of the imagination, even should the reigning theories subsequently be confirmed, would not fail to bring many neglected facts into their rightful place.

I am old enough to remember when the cell held a very subordinate position in Neurology, and now my meditations have led me to return, if not to the old views of the cell, at least to something like the old estimate of its relative importance. Its existence was first brought prominently forward by Ehrenberg in 1834, who described its presence in the sympathetic ganglia; and by Remak in 1837, who described it in the spinal ganglia. For some time afterwards the ganglia and centres were said to contain irregular masses of vesicular matter which were looked on as investing the fibres; what their office was, did not appear. But there rapidly arose the belief that the cells were minute batteries in which "nerveforce" was developed, the fibres serving merely as conductors. Once started on this track, Hypothesis had free

way, and a sort of fetichistic deification of the cell invested it with miraculous powers. In many works of repute we meet with statements which may fitly take their place beside the equally grave statements made by savages respecting the hidden virtues of sticks and stones. We find the nerve-cells credited with "metabolic powers," which enable them to "spiritualize impressions, and materialize ideas," to transform sensations into movements, and elaborate sensations into thoughts; not only have they this "remarkable aptitude of metabolic local action," they can also "act at a distance." The savage believes that one pebble will cure diseases, and another render him victorious in war; and there are physiologists who believe that one nerve-cell has sensibility, another motricity, a third instinct, a fourth emotion, a fifth reflexion: they do not say this in so many words, but they assign to cells which differ only in size and shape, specific qualities. They describe sensational, emotional, ideational, sympathetic, reflex, and motor-cells; nay, Schröder van der Kolk goes so far as to specify hunger-cells and thirst

*

*LUYS, 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 saurait 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.

cells.*

With what grace can these writers laugh at Scholasticism?

134. The hypothesis of the nerve-cell as the fountain of nerve-force is supported by the gratuitous hypothesis of cell-substance having greater chemical tension and molecular instability than nerve-fibre. No evidence has been furnished for this; indeed the only experimental evidence bearing on this point, if it has any force, seems directly adverse to the hypothesis. I allude to the experiments of Wundt, which show that the faint stimulus capable of moving a muscle when applied directly to its nerve, must be increased if the excitation has to pass through the cells by stimulation of the sensory nerve.† Wundt interprets this as proving that the cells retard every impulse, whereby they are enabled to store up latent force. The cells have thus the office of locks in a canal, which cause the shallow stream to deepen at particular places. I do not regard this interpretation as satisfactory; but the fact at any rate seems to prove that so far from the cells manifesting greater instability than the fibres, they manifest less.

135. The hypothesis of nerve-force being developed in the ganglia, gradually assumed a more precise expression when the nerve-cells were regarded as the only important elements of a ganglion. It has become the foundationstone of Neurology, therefore very particular care should be taken to make sure that this foundation rests on clear and indisputable evidence. Instead of that, there is absolutely no evidence on which it can rest; and there is much evidence decidedly opposed to it. Neither struc*SCHRÖDER VAN DER KOLK, Pathologie der Geisteskrankheiten, 1863,

p. 69.

+ WUNDT, 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.

ture nor experiment points out the cells as the chief agents in neural processes. Let us consider these.

Fig. 22 shows the contents of a molluscan ganglion which has been teased out with needles.

[graphic]
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Cells, fibres, and amorphous substance from the ganglion of a mollusc

(after Bucholtz).

The cells are seen to vary in size, but in all there is a rim of neuroplasm surrounding the large nucleus, and from this neuroplasm the fibre is seen to be a prolongation. The dotted substance in the centre is the neuroglia. Except in the possession of a nucleus, there is obviously here no essential difference in the structure of cell and fibre.

Now compare this with Fig. 23, representing three fibres from the auditory nerve.

Here the cell substance, as Max Schultze remarks, "is a continuation of the axis cylinder, and encloses the nucleus. The medulla commonly ceases at the point where the axis enters the cell, to reappear at its exit; but it sometimes stretches across the cell to enclose it also: so that such a ganglion cell is in truth simply the nucleated portion of the cylinder axis." There are many places in which fibres are thus found with cells inserted in their course as swellings: in the spinal ganglia of fishes these are called bipolar cells; they are sometimes met with even in the cerebellum; but oftener in peripheral nerves, where they are mostly small masses of granular neuroplasm from which usually auditory nerve. a, the axis a branching of the fibre takes place. cylinder; b, the cellular enThe point to which attention is called sheath.

[graphic]

Fig. 23.-Fibres from the

largement; c, the medullary

TRINCHESE also says that the fibres "provengono dalle cellule e non son altro che i loro prolungamenti o poli."-Op. cit., p. 13. An

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