OF THE CEREBELLUM, AND ITS FUNCTIONS. 737 



769. Among the arguments adduced by Gall and his followers in proof of the 

 connection between the Cerebellum and the sexual instinct, is one which would 

 deserve great attention, if the facts stated could be relied on. It has been as- 

 serted, over and over again, that the Cerebellum, in animals which have been 

 castrated when young, is much smaller than in those which have retained their 

 virility being, in fact, atrophied from want of power to act. Now it is unfor- 

 tunate that vague assertion, founded on estimates formed by the eye from the 

 cranium alone, is all on which this position rests ; and it will be presently shown 

 how very liable to error such an estimate must be. The following is the result 

 of a series of observations on this subject, suggested by M. Leuret, 1 and car- 

 ried into effect by M. Lassaigne : The weight of the Cerebellum, both abso- 

 lutely, and as compared with that of the Cerebrum, was adopted as the standard 

 of comparison. This was ascertained in ten Stallions, of the ages of from 

 nin3 to seventeen years ; in twelve Mares, aged from seven to sixteen years; 

 snd in twenty-one Geldings, aged from seven to seventeen years. The average 

 weight of the Cerebrum in the Stallions was 433 grammes ; the greatest being 

 485 gr., and the least (which was in a horse of ten years old) being 350 gr. 

 The average weight of the Cerebellum was 61 gr. ; the greatest being 65 gr., 

 and the least 56 gr. The average proportion borne by the weight of the Cere- 

 bellum to that of the Cerebrum was, therefore, 1 to 7.07 ; the highest (result- 

 ing from a very small Cerebrum) being 1 to 6.25 ; and the lowest (resulting 

 from an unusually large Cerebrum) being 1 to 7.46. Throughout it might be 

 observed that the variation in the size of the Cerebellum was much less than 

 in that of the Cerebrum. In the twelve Mares, the average weight of the 

 Cerebrum was 402 gr. ; the highest being 432 gr., and the lowest 363 gr. 

 That of the Cerebellum was 61 gr. ; the highest being 66 gr. (which was in the 

 individual with the smallest Cerebrum), and the lowest 58 gr. The average 

 proportion of the weight of the Cerebellum to that of the Cerebrum was 1 to 

 6.59 ; the highest being 1 to 5.09, and the lowest 1 to 7. The proportion was, 

 therefore, considerably higher in the perfect female than in the perfect male. 

 In the twenty-one Geldings, the average weight of the Cerebrum was 419 gr. j 

 the highest being 566 gr., and the lowest 346 gr. The average of the Cere- 

 bellum was 70 gr. ; the highest being 76 gr., and the lowest 64 gr. The ave- 

 rage proportion was, therefore, 1 to 5.97 ; the highest being 1 to 5.16, and the 

 lowest 1 to 7.44. It is curious that this last was in the individual which had 

 the largest Cerebellum of the whole ; but the proportional weight of the Cere- 

 brum was still greater. Bringing together the results of these observations, 

 they are found to be quite opposed to the statement of Gall. The weight of 

 the Cerebrum, reckoning the Cerebellum as 1, is thus expressed in each of 

 the foregoing descriptions of animals : 



Average. Highest. Lowest. 



Stallions 7.07 7.46 6.25 



Mares 6.59 7.00 5.09 



Geldings 5.97 7.44 5.16 



The average proportional size of the Cerebellum in Geldings, therefore, is so 

 far from being less than that which it bears in entire Horses and Mares, that it 

 is positively greater; and this depends not only on diminution in the relative 

 size of the Cerebrum, but on its own larger dimension, as the following com- 

 parison of absolute weights will show : 



Average. Highest. Lowest. 



Stallions '-';.. . . . 61 65 56 



Mares . . . - . . ' . 61 66 58 



Geldings * ' ; ... 70 76 64 



1 "Anat. Comp. du SystemeNerveux," torn. i. p. 427. 



47 



