About a hundred years ago it was shown by Gall—who was attacked by several authors, among them Rieger, as innovations always are, but who was also successfully defended by the celebrated German nerve specialist and philosopher, Moebius[93]—that castrated animals or persons have an alteration in the back part of the skull indicating an impoverishment of the cerebellum. And, indeed, he produces his own evidence and that of several other authorities, Darnecy, Rousseau, etc., which gives the history of several autopsies on castrated persons, all of whom showed an atrophy of this structure. In cases where only one of the testicles was destroyed, this atrophy was always present in the hemisphere of the small brain on the opposite side. Footnote 93: Moebius: “Die Wirkungen der Castration,” Halle, 1902. It has been found by numerous authorities that the skull and brain of castrated animals and persons is smaller than the normal. Gall[94] noted this fact, and after him Vimont,[95] from experiments on animals; and, according to the latter observer castration of both sides produces a considerable diminution of the cerebellum. Leuret and Hoffmann[96] found a diminution of the head in horses, sheep, and pigs after such an operation, and that the other parts of the skeleton are always altered is a fact recorded by a large number of authorities as stated already. Footnote 94: Gall: “Anatomie et Physiologie du Système nerveux,” T. iii., p. 108, Paris, 1818. Footnote 95: Vimont: “Traité de Phrenologie humaine et compareè,” two vols. et atlas, vol. ii., p. 233, Paris, 1835. Footnote 96: Hoffmann: “Ueber die Castration der Hausthiere Schneidermühls Thier medecin,” Vorträge ii., 12. 1892. As we have pointed out above, any alteration of the testicles or ovaries is followed by nervous disturbances, and, consequently, the total removal of these glands produces far more deleterious effects, and these will vary according to whether such persons have been castrated at an early age or later. In these latter cases nervous disorders will be more acutely felt, and as the celebrated French authority, Dupuytren, states, melancholia is a common phenomenon in castrated men. According to more recent observations in cases of enlargement of the prostate that have been treated by castration, the patients exhibit melancholia. We may here remark that the testicles and the prostate are in close relation, the latter always becoming atrophied after castration. There is experimental evidence to show that a too large amount of testicular or ovarian secretion may produce toxic effects. Thus, Loisel, by injecting testicular or ovarian extracts into animals, could produce toxic symptoms in every instance. This may account for the fact mentioned previously that persons living for a long time in complete sexual abstinence, occasionally exhibit symptoms of disorder of the nervous system.