THE SPINAL CORD AND CEREBELLUM 143 



we recover our balance by a violent muscular contrac- 

 tion. What part in all this does the cerebellum play, 

 unless it be that of increasing the motor impulse, to 

 the group of muscles set in motion ? or, if we put it 

 otherwise, what factor is wanting to complete the 

 process ? 



In the cerebellum there are three main elements — The ana- 

 tomical 



the cells of the rust-coloured layer, those of the elements 



m equili- 



molecular layer, and Purkinje's cells. What are the bration. 

 functions of these, and in what way did they con- 

 tribute to the recovery of our balance ? Was there 

 any sensory element in the sequence of nervous acts 

 which could not be accounted for by referring it to 

 the cerebrum? Let us suppose that the sensory 

 elements alluded to above were reduplicated in the 

 cerebellum : for what purpose would such a reduplica- 

 tion take place unless it were to borrow force from 

 the great cells of Purkinje ? 



That it could not be for the sake of bringing about 

 co-ordination pure and simple is evident, for we have 

 co-ordination in the absence of the cerebellum.* 



The will as a factor in this problem is one of such 

 importance that further inquiry into the part which it 

 plays in equilibration is necessary. We have already 



* Ferrier, loc. cit., p. 181 : ' If the cerebellum were indis- 

 pensable, according to the doctrines of Flourens, for the co- 

 ordination of movements, it would be impossible to harmonize 

 the actual facts of clinical observation with an hypothesis so 

 formulated ; for it should have been impossible for Alexandrine 

 Labrosse to walk at all if the co-ordinated movements of locomo- 

 tion were dependent on the cerebellimi,' 



