Stroud, Mammalian Ccrebclhim. 85 



But it has taken so firm a root in the literature, that it might be 

 unwise to discard it. It simply designates the mesal part of the 

 cerebellum and is a secondary development. 



The vermis as it exists in the adult brain is not present in 

 early embryos.^ See also Plate I, Figs. 8 and 10, Plate V, Fig. 

 56, Plate VI, Fig. 58. 



The writer fails to recognize it in his specimens till the 

 other parts are quite far advanced in development. Compare 

 Figs. 17, 20, 69, and 72. Considering the mode of develop- 

 ment, the term fasiigiuni would be more appropriate than 

 vermis. 



Hemispheres, Lateral lobes. — The cerebellum is commonly 

 described as consisting of three parts, a middle part, vermis, 

 and two lateral parts, the so-called lateral lobes, or hemispheres. 

 This, it is true, is the apparent condition in man, but we shall 

 show later that it is not the real condition, for the parts which 

 seem to be lateral are so because their excessive development 

 has overshadowed and concealed parts which lie still farther 

 laterad. This is clearly seen in the lower mammals. 



The mammalian cerebellum presents at least four distinct 

 regions; viz., one mesal and three lateral regions. 



1. The middle part (vermis). 



2. The pileum (hemisphere or lateral lobe). 



3. Paraflocculus (accessory flocculus). 



4. Flocculus. 



These regions will be discussed farther on. 



Historical. 



During the first quarter of this century an interest began 

 to be manifested in the development of the cerebellum. The 

 writings of one French and three German investigators upon 

 this subject are recorded. 



The first work that I have found mentioned was in 18 12, 

 by los. et Car. Wenzel (33, 256). It is quoted by Burdach (3, 



^This was mentioned by Wilder (37, p. 125.) 



