242 PHYSIOLOGICAL SERIES. 



The whole of the anterior surface of this mass is separated 

 from the rest of the cerehellum by means of the deepest, 

 fissure which crosses the middle line. This we may dis- 

 tinguish as the anterior lobe, and its limiting fissure may 

 be called " primary/' as it is the first fissure to cross the 

 middle line in the course of development. It corresponds to 

 the preclival fissure of Human Anatomy. The anterior lobe 

 represents the lobus centralis and lobus culminis of Human 

 Anatomy. It is a large lozenge-shaped area, broad in the 

 mesial plane and rapidly tapering towards the middle 

 peduncle and the front of the paraflocculus on each side. 



The most caudal or rather caudo-ventral part of the 

 cerebellum consists of a small mesial mass, the grey matter 

 of which is not continued laterally, as that of the rest of 

 the mesial cerebellar areas is. This may be distinguished 

 as the posterior lobe and its dorsal limiting fissure as 

 u secondary." The lobe represents the nodnlus and uvula 

 of Human Anatomy. Laterally it appears to be prolonged 

 into a narrow medullary band, which is closely connected 

 with the posterior medullary velum and leads to the 

 flocculus. 



The great mass included between the primary and 

 secondary fissures and limited laterally by the floccular 

 fissures may be called the '* central " or preferably (to avoid 

 confusion with the " central lobe " of Human Anatomy) 

 the " middle lobe." 



The middle lobe is divisible into four parts, the behaviour 

 of the lateral parts of each of which differs markedly from 

 that of the others. 



The anterior lobule consists of a narrow band, which 

 becomes slightly constricted on each side of the middle line 

 and then expands again to a slight extent to form a long 

 tapering fissured band, which forms the posterior lip of the 

 primary fissure. In Man this becomes greatly expanded 

 to form the lobus clivi. 



The second lobule is narrow in the mesial plane, but 

 expands enormously to form the great suprafloccular (i.e. 

 i.l.ove the paraflocculus) mass, the folia of which arc 

 arranged in a feather-like pattern in all the Oarnivora. 

 It presents a similar arrangement in the Anteaters, the 



