Stroud, Mammalian Cerebellum, 79 



Plate IV shows sections of both kitten and human cerebellums. 

 Plates V to VIII show gross preparations of embryonic human 

 cerebellums. 



In the figures no attempt has been made to show parts 

 other than those concerned in the subject of this paper ; but 

 to facilitate orientation the oblongata, the mesencephal, and in 

 a few cases the cerebrum have been added in outline. 



Defects. — Material and time to trace every consecutive 

 step in the development of the cerebellum are lacking ; but it is 

 believed that the most important stages have been studied and 

 discussed. The conclusions given are to be regarded as the 

 writer's interpretation of his available material and subject to 

 such modifications as further research may require. 



Tetminology. 



A careful study of the cerebellum in the different groups 

 of mammals will convince even the most sceptical that the de- 

 scriptions found in the present standard works on encephalic 

 anatomy are inadequate for an exact comprehension of this 

 important organ ; i. e., the mammalian cerebellum does not fit 

 the description. 



If we take a cerebellum from each of the fourteen orders 

 of mammals, beginning with the monotremes and ending with 

 the primates, at first sight one would say that they are as un- 

 like as are cats from horses. But closer inspection shows that 

 they all agree in certain fundamental characters. 



On the other hand it may be said that a given region 

 which is very prominent in the cerebellums of animals belong- 

 ing to one order may in another order be so reduced and over- 

 shadowed by adjacent parts as to be altogether overlooked. 



It may not be clear at first but my investigations have con- 

 vinced me that there is one fundamental plan for the cerebellum 

 running throughout all mammalia, but that this plan is various- 

 ly elaborated in the different orders. 



Therefore the writer ventures to suggest that our present 

 conception of the cerebellum is incomplete. 



Perhaps the greatest cause for this misconception lies in the 



