Page:Popular Science Monthly Volume 14.djvu/504

488 faculties. "A man," as we remember hearing a phrenological lecturer say, "with a head bulging out behind, is going backward in the world"; and there was indeed, as we shall see, a modicum of truth (although he knew and understood it not) in the lecturer's remark, since without the cerebellum we could in reality proceed neither forward nor backward. We now know that the old phrenology of the cerebellum is utterly wrong and unfounded. The new phrenology has shown us that in cases of diseased animal appetites, which in our lunatic asylums are but too frequently represented, the cerebellum is not found to be affected—a result explained by the fact that the appetites referred to are indeed as much part of our "mental" constitution as is the exercise of benevolence or of any other mental faculty. Furthermore, the new phrenology supplies positive evidence as to the true functions of the cerebellum. When it is removed from a pigeon, for instance, the animal retains its faculties, it will feed, it can see and hear, but is utterly unable to maintain its equilibrium. If thrown into the air, it flaps its wings in an erratic and aimless fashion. In one word, it can not "coordinate" its movements, that is, it can not so adjust the motions of one set of muscles as to bring them into purposive harmony with another set or series. The cerebellum thus appears to be the great brain center whence are issued the commands and directions which guide the muscular actions and movements of our lives. Contrariwise, the true functions of the cerebellum are proved by experiments in which this part of the brain has been left intact while the cerebrum or true brain has been removed—an operation absolutely painless, as will presently be more particularly mentioned. A bird or higher animal in such a case will lose all power of volition; it will be deprived of sight, hearing, and other senses; it will die of hunger unless fed; it will exhibit no desire to move; and will in short present a condition utterly opposed to that seen when the cerebellum is removed and the true brain left intact. But with its cerebellum present, and minus its true brain, the bird can perfectly "coördinate" its movements. It will fly straight if thrown into the air, it will walk circumspectly enough if pushed forward, and will exhibit in fact such perfect muscular control, despite its want of volition and intellect, that the functions of the cerebellum as a controller of movements are no longer matter of hypothesis, but have become stable physiological fact.

If, however, the old phrenology has been displaced from the cerebellum by the new, no less important is it to note that, regarding the functions of the true brain, modern research has been equally successful in deposing the old ideas of the "organs" and their attendant faculties as exhibited on the phrenological charts and busts. Experimentation on the brain of higher animals, quoad the brain itself, is absolutely painless—contrary to popular notions and ideas. True, there are certain parts of the brain which are exceedingly delicate, and in which the point of a needle would inflict at once a fatal injury. But the