FUNCTIONS OF THE CEREBELLUM. 719 



cannot fail to show a great difference between the phenomena following cerebellar dis- 

 ease and the muscular phenomena due to well-marked and persistent vertigo. 



Connection of the Cerebellum, with the Generative Function. The fact that the cere- 

 bellum is the centre for equilibration and the coordination of certain muscular move- 

 ments does not necessarily imply that it has no other functions. The idea of Gall, that 

 "the cerebellum is the organ of the instinct of generation," is sufficiently familiar; and 

 there are numerous facts in pathology which show a certain relation between this nerve- 

 centre and the organs of generation, although the idea that it presides over the genera- 

 tive function is not sustained by the results of experiments upon animals or by facts in 

 comparative anatomy. 



In experiments upon animals in which the cerebellum has been removed, there is noth- 

 ing pointing directly to this part as the organ of the generative instinct. Flourens re- 

 moved a great part of the cerebellum in a cock. The animal survived for eight months. 

 It was put several times with hens and always attempted to mount them, but without 

 success, from wanf of equilibrium. In this animal, the testicles were enormous. This 

 observation has been repeatedly confirmed, and there are no instances in which the cere- 

 bellum has been removed with apparent destruction of sexual instinct. In a comparison 

 of the relative weights of the cerebellum in stallions, mares, and geldings, Leuret found 

 that, far from being atrophied, the cerebellum in geldings was even larger than in either 

 stallions or mares. 



In the numerous cases of disease or injury of the cerebellum, to which we have 

 referred, there are some, in which irritation of this part has been followed by per- 

 sistent erection and manifest exaggeration of the sexual appetite, and others, in which 

 its extensive degeneration or destruction has apparently produced atrophy of the genera- 

 tive organs and total loss of sexual desire. There are also certain cases of this kind 

 which we have not yet cited. Serres gives the history of several cases, in which irrita- 

 tion of the cerebellum was followed by satyriasis or nymphomania, but, in other cases, 

 there were no symptoms referable to the generative organs. In the case reported by 

 Combette, the patient had the habit of masturbation. Dr. Fisher, of Boston, reported 

 (1838) two cases of diseased or atrophied cerebellum, with absence of sexual desire, 

 and one case of irritation, with satyriasis. Similar instances are given by other writers, 

 which it is unnecessary to detail. We have already cited the observations of Budge, in 

 which mechanical irritation of the cerebellum was followed by movements of the uterus, 

 testicles, etc. 



Although there are many facts in pathology which are opposed to the view that the 

 cerebellum presides over the generative function, there are numerous cases which go to 

 show a certain connection between this portion of the central nervous system and the 

 organs of generation in the human subject. But this is all that we can say upon this 

 important point ; certain it is that the facts are not sufficiently numerous, definite, and 

 invariable, to sustain the doctrine that the cerebellum is the seat of the sexual instinct. 



Development of the Cerebellum in the Lower Animals. The study of the comparative 

 anatomy of the cerebellum has little physiological interest, except in so far as it bears 

 upon our knowledge of its functions. From this point of view, there is little to be said 

 concerning its development in the animal scale. We can hardly establish a definite rela- 

 tion between this particular part of the encephalon and the complicated character of the 

 muscular movements ; for, as we pass from the lower to the higher orders of animals, we 

 have other parts of the brain, as well as the cerebellum, developed in proportion to the 

 increased complexity of the muscular system. Nor can we connect the comparative 

 anatomy of the cerebellum with the ideas of the functions of this organ in connection 

 with generation. The amphioxus lanciolatus has no cerebellum, and this organ, there- 

 fore, is not indispensable to generation. In some animals remarkable for salacity, the 

 cerebellum is not unusually large ; and facts of this kind might be multiplied ad injinitum. 



