But as to the pretended organs of the brain, are they really situated at the surface of the brain, as Gall asserts? In plain terms, is the surface of the brain the only active part of the organ? Here is a physiological experiment that shows how very much mistaken Gall is.
You can slice off a considerable portion of an animal’s brain, either in front, behind, on one side, or on the top, without his losing anyone of his faculties.[106]
The animal may, therefore, lose all that Gall calls surface of the brain, without losing any of his faculties. Therefore it cannot be that the organs of the faculties reside at the surface of the brain.
And comparative anatomy is not less opposite to Gall’s opinions than is direct experiment itself. I shall not follow him here in the detail of his localizations. How could these localizations have any meaning? He does not even know whether an organ is a fascicle of fibres, or a fibre.[107]
For example; he places what he calls the instinct of propagation in the cerebellum, and what he calls the instinct of the love of offspring, in the posterior cerebral lobes; and he looks upon these two localizations as the very surest in his book.
“I should wish,” says he, “that all young naturalists might begin their researches with the study of these two organs. They are both easily to be recognised,”[108] &c.
What! The cerebellum, so different in its structure from the great brain, is the cerebellum, like the brain,[109] to be considered an organ of instinct? And what is more, is it to be regarded as the organ of a single instinct only, while the brain shall have twenty-six of them?
I have already said that the cerebellum is the seat of the principle that presides over the locomotion[110] of the animal, and that it is not the seat of any instinct.
Gall places the love of offspring in the posterior lobes of the brain.[111] Now, the love of offspring, and especially maternal love, is every where to be found among the superior animals; it is found in all the mammifera, in all the birds.[112] The posterior lobes of the brain, therefore, ought to be found in all these beings. Not at all: the posterior lobes are wanting in most of the mammifera; they are wanting in all the birds.
Gall locates the faculties that are common to both man and animals, in the posterior part of the brain; in the anterior part he places those[113] that are peculiar to man alone. According to this plan, the most persistent portion of the brain will be the posterior portion, and the least persistent the anterior portion. But the inverse of the proposition holds. The parts that are most frequently wanting are the posterior parts, and those that are most invariably present are the anterior parts.[114]