10 



ROBERT S. ELLIS 



The values given in the table do not seem to indicate a positive 

 correlation between reproductive activity and the relative weight 

 of the cerebellum, but they do seem to indicate a negative one, 

 which would be quite as hard to understand. To throw any light 

 possible on the question, I studied the weights of the parts of the 

 brain in the male albino rat after castration. The data for this 

 purpose were kindly offered me by Doctor Hatai, and for the 

 details of the experiment the reader is referred to his paper ('15). 

 From his results I have arranged table 6. 



TABLE 5 



The relative weight of the cerebellum in stallions, geldings and mares {after Leuret) 



TABLE 6 



The effect of gonadectomy on the relative weights of the parts of the brain of the 

 albino rat based on the work of Hatai, 1915 



As will be observed from the table, there is no change in the 

 relative weight of the cerebellum of the male albino rat as a 

 result of gonadectomy. In view of the relations in the rat, in- 

 terpretation of the figures given by Leuret for horses is not easy, 

 but at least it seems clear that his results do not agree with any 

 of the theories so far advanced. 



In this connection it is desirable to examine the view of Mar- 

 shall ('92), who concludes, on the basis of his excellent classifica- 

 tion of Boyd's results, that the cerebellum is relatively heavier 



