354 FUNCTIONS OF THE NERVOUS SYSTEM. 



sembling that described by Flourens as resulting from partial injury of this 

 organ. In a few cases in which both lobes of the Cerebellum have been 

 seriously affected, the tendency to retrograde movement has been observed ; 

 and instances are also on record, of the occurrence of rotatory movement, 

 which has been found to be connected with lesion of the Crus Cerebelli on 

 the same side. So far as they can be relied on, therefore, the results of the 

 three methods of investigation bear a very close correspondence ; and it can 

 scarcely be doubted that they afford us some approximation to truth. 



466. We have now to examine, however, another doctrine regarding the 

 functions of the Cerebellum, which was propounded by Gall, and which is 

 supported by the Phrenological school of physiologists. This doctrine 

 that the Cerebellum is the organ of the sexual instinct is by no means in- 

 compatible with the other ; and by some it has been held in combination with 

 it. The greater number of Phrenologists, however, regard this instinct as the 

 exclusive function of the Cerebellum ; and assert that they can judge of its 

 intensity, by the degree of development of the organ. We shall now exam- 

 ine the evidence in support of this position, afforded by the three methods of 

 inquiry which have been already indicated. The results of fair observation 

 as to the comparative size of the Cerebellum in different animals, can scarcely 

 be regarded as otherwise than very unfavourable to the doctrine in question. 

 In the greatest number of Fishes, it is well known that no sexual congress 

 takes place ; the seminal fluid being merely effused, like any other excretion, 

 into the surrounding water ; and being thus brought into accidental contact 

 with the ova, of which a large proportion are never fertilized. But there are 

 certain Fishes, as the Sharks, Rays and Eels, in Avhich copulation takes place 

 after the ordinary method. Now on contrasting these two groups, we find no 

 corresponding difference in the size of the Cerebellum. It is true that this 

 organ is of large size in the Sharks ; but it is very small in the Rays ; and 

 almost rudimentary in the Eels : in this respect bearing a precise correspond- 

 ence with the variety and complexity of their movements. Further, in many 

 ordinary Fishes, which do not copulate, such as the Cod, the Cerebellum is 

 not only larger, but more complex in structure, than it is in the generality of 

 Reptiles, in which the sexual instinct is commonly strong ; the whole spinal 

 system of the Frog possessing, at the season of reproduction, an extraordinary 

 degree of excitability, which is evidently destined to aid in the performance 

 of the function ( 401, ). Again, in comparing the Gallinaceous Birds, 

 which are polygamous, with the Raptorial and Insessorial tribes which live 

 in pairs, we find that the former, instead of having a larger cerebellum, have 

 one of inferior size. Further on looking at the Mammalia, the same dispro- 

 portion may be noticed. A friend who kept some Kangaroos in his garden, 

 informed the Author that they were the most salacious animals he ever saw ; 

 yet their Cerebellum is one of the smallest to be found in the class. Every 

 one knows, again, the salacity of Monkeys ; there are many which are excited 

 to violent demonstrations by the sight even of a human female; and there 

 are few which do not practise masturbation, when kept in solitary confinement: 

 yet in them the Cerebellum is much smaller than in Man, in whom the sexual 

 impulse is much less violent. It has been supposed that the large size of the 

 organ in Man is connected with his constant possession of the appetite, which is 

 only occasional in others ; but this does not hold good; since among domestic 

 animals, there are many Avhich are ready to breed throughout the year, Cats 

 and Rabbits for instance ; and in these we do not find any peculiar difference 

 in the size of the Cerebellum. It is asserted, however, that the results of 

 observation in Man lead to a positive conclusion, that the size of the Cere- 

 bellum is a measure of the intensity of the sexual instinct in the individual. 

 This assertion has been met by the counter-statement of others, that no 



