424 



PHYSIOLOGY 



CHAP. 



correlating the relative development of different lobes in different 

 mammals with the degree of functional development of certain 

 groups of muscles, to argue in favour of a physiological connection 

 a functional relation between the central and peripheral 

 variations. Bolk's ingenious inductions, taken as the starting- 

 point of new physiological researches, have led to certain positive 

 results in regard to functional localisation in the different 

 cerebellar lobules. 



As regards the structure of the cerebellum, we must confine 

 ourselves to certain general statements, referring for minute 



culmen. 

 mo'ntic.u.li. 



SuZcus 



precliua.lis 

 ~ \ 



Sultus post- cen-tralis 

 loiuLus cen-tr 



lin 



nocLu-ius 



FIG. 223. Median section of vermis. Light yellow, Bolk's anterior lobe ; dark yellow, 

 the two median lobules. 



details to recent text-books on the anatomy and histology of the 

 nervous system. 



If a section is made through the cerebellum in the median 

 sagittal line, it is seen to consist of a central^ white substance 

 covered by a uniform layer of grey cortical matter (Fig. 224). The 

 lamellar or foliated aspect of the surface of the cerebellum is pro- 

 duced by the terminal branches of the so-called " arbor vitae," 

 covered with grey matter. 



Each lamella shows in section a central zone, of white matter, 

 and a cortex of grey matter consisting of two layers, one of which 

 is termed granular because it contains small nerve-cells which 

 look like granules with low magnification, the other molecular 

 owing to its appearance under the microscope. Between the two 

 layers there is a layer of large nerve-cells, known as the cells or 

 corpuscles of Purkinje (Fig. 224). 



