Psychos is the result of evolutionary development, and the chief reason why insanity is not as prevalent in the savage as in the civilized man, is because the brain of the savage lacks development. I do not wish to convey the idea that insanity is purely psychical in its nature. Insanity is the result of a material change in the structure of the brain produced by morbific action. The manifestations of insanity are merely the symptoms of a disease that involves the brain. The savage has less development of psychical function, consequently he is less liable to mental lesion. I mean by psychical function that portion of the brain in which psychos has its origin. Alienists consider the habits of men as being the factor in the production of insanity. Habits and heredity are undoubted factors in the production of diseased minds, and, in fact, are the chief agents. You cannot, however, expect to find a disordered function where that function is absent. Savages have paresis, apoplexy, and imbecility, seldom or never insanity. The reason is patent--they lack the psychic function, that peculiar element, whatever it may be, which raises civilized man so high above them. That this element can be developed in savages I do not for one instant deny. The ploughshare of evolutionary civilization will bring it to the surface sooner or later, and when it does insanity follows. I have only to point to the American negro to prove the truth of my proposition; even he is partially exempt, simply because his civilization is of such recent date that his brain has not yet acquired its full quota of the psychic element. I will venture to assert, so true is the fact that insanity is the product of civilization, that, if it were not for the combating influences of social laws, assisted not a little by scientific medical aid, all North America could not contain the vast and enormous army that would constitute the civilized world's array of lunatics.