ISO THE SPINAL CORD AND CEREBELLUM 



of that organ from various animals, but not one of 

 which it can be said that the vital powers were not 

 lowered, nor which terminated otherwise than fatally 

 within a relatively brief period. Experimental in- 

 vestigation also shows that when one-half of the 

 cerebellum is removed, the pyramidal tract on the 

 same side, and with it the anterior roots of the spinal 

 nerves, degenerate.* 

 Develop- The mode of growth of the cerebellum also throws 



ment of . ... 



the cere- some light upon its functions. In the infant it is 

 relatively very small, its weight being, according to the 

 computation of some authorities, only one-twentieth 

 of that of the cerebrum, whilst in the adult it is about 

 one-eighth. The proportion the two organs bear to 

 one another is not the same in the two sexes ; in the 

 male it is as 1 is to 8f , in the female as 1 is to 85-. 

 We cannot decide from these figures whether the 

 cerebellum is greater in the female or the cerebrum 

 smaller, but there is authority for the statement that 

 the increase in size of the cerebellum after the 

 fourteenth year is greater in the female than in the 

 male.f Why should this be so ? Does it not 

 correspond, coming as it does at the age of puberty, 

 with the fact that a greater demand may from that 

 time be made on the metabolic or building-up powers 

 of the weaker sex ? How also, one may ask, could 

 the activity of the womb in pregnancy react in so 

 marked a manner as is the case on the development 



* Bechterew, loc. cit., p. 96. 

 t Gray's 'Anatomy,' p. 728. 



