VIII 



THE HIND-BRAIN 



479 



posterior part of the veriuis, 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 



Si- 



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 Rynberk 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- jf 

 cumscribed extirpations of certain & 

 lobules, and to this end performed 

 numerous experiments in the 

 Physiological Institute in Rome 

 (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 



.,, T v $ V. , Fio. 241. Sagittal section of dog's cere- 



Well aS a Sagittal Section, Which bellum to show depth of sulci. The 



ollrv,T7o nc fr nrvrnrkafo rlo-nfV>a nf abbreviations on both these figures refer 



allOWS Ub tO COinpaie deptns Ol to the diagram of Fig. 239. 



the interlobar and interlobular 



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



composed (Fig. 241). 



The new facts established by van Rynberk may be grouped as 

 follow;-? : 



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



