[183] Anat. et Physiol. du Système Nerveux, &c. iii. 15.
[184] The white matter is every where fibrous. No person has contributed more than Gall to the demonstration of this great fact. He justly remarks: “Those authors who, with Sœmmerring and Cuvier, &c., recognise the fibrous structure of the brain, in many of its parts, have nevertheless, not yet ventured to say that it is so in all its parts.”—T. i. 235.
[185] The cerebellum serves only for the motions of locomotion. (See the first article of this work.) But, I am here setting forth Gall’s opinions.
[186] “The particular systems of the brain terminate in fibrous expansions arranged in layers, just as the other nervous systems expand in fibres at their peripheral extremity.”—T. i. 318. “All the diverging bundles of the brain, after they come out from the last apparatus of reinforcement, expand in layers and form convolutions.”—T. i. 283. “The nerves of sensation and motion expand in the skin and the muscles; the nerves of the senses, each in the external instrument to which they belong: for example, the pituitary membrane upon the bones of the nose: the nerve of taste in the tongue, and the expansion of the optic nerve in the retina.... Nature obeys precisely the same law in the brain. The different parts of the brain originate and are reinforced at different points; they form fibrous bundles of various sizes, which terminate in expansions. All these expansions of the various bundles constitute, when reunited, the hemispheres of the brain.”—T. iii. p. 3.
I here speak only of the diverging fibres. Coming from the interior, they proceed towards the exterior: the converging fibres coming from the exterior, that is, according to Gall, from the gray matter that envelopes the brain and the cerebellum, are directed inwards. The former constitute the convolutions, while the latter compose the commissures. But I shall, further on, return to this subject.
[187] See my work, De l’instinct et de l’intelligence des animaux, &c. p. 46, 2d edit.
[188] Opus citat. p. 49.
[189] T. iii. p. 64.
[190] T. iii. p. 64.
[191] T. iii. p. 64.