VIII 



THE HIND-BRAIN 



479 



posterior part of the vermis, the tendency was to fall backwards. 

 Thomas (1897), on the contrary, found a special relation in dogs 

 between the vermis and the muscles of the anterior portion of the 



.- fv 



'--.//> 



L ans 



FIG. 240. Lobular division of dog's cerebellum. (Bolk.) 



trunk, and between the hemispheres of the cerebellum and the 

 muscles of its posterior portion. 



But it was van Eynberk who first provided an experimental 

 basis for the theory of cerebellar 

 localisation, taking as his guide 

 Bolk's work on the comparative 

 anatomy of the mammalian cere- 

 bellum. 



He attempted to test Bolk's 

 inductions experimentally by cir- 

 cumscribed extirpations of certain '*>? *" 

 lobules, and to this end performed \ ,-,, 

 numerous experiments in the 

 Physiological Institute in Rome 



*/ o 



(1904-8). As all his work was 



carried out on the dog it is useful 



in the two accompanying figures 



to reproduce a diagram of the dog's 



cerebellum divided into lobules 



according to Bolk (Fig. 240), as 



well as a sagittal section, which 



allows us to compare depths of 



the inteiiobar and interlobular 



sulci, and the varying size of the lamellae of which the lobules are 



composed (Fig. 241). 



The new facts established by van Ryuberk may be grouped as 

 follows : 



(a) After the total or partial extirpation of the lobulus simplex 



;. 241. Sagittal section of dog's cere- 

 bellum to show depth of sulci. The 

 abbreviations on both these figures refer 

 to the diagram of Fig. -J3'.'. 



