PAPIO O'NOCEPHALUS 319 



configuration of the dentate nueleus are therefore of significance as 

 showing to what degree the cerebeUum contributes to the function of 

 coordination. This nucleus in lower primates is a diffuse mass of cells 



FIG. 149. BABOON. LEVEL OF THE CEREBELLAR NUCLEI. 



CBL, Cerebellum; ndt. Cerebellar Nuclei, Lateral Group; nfg. Cerebellar Nuclei, Mesial Group; ver, Vermis 

 Cerebelli. [Accession No. 150. Section 165. Actual Size 37 X 23 mm.] 



without convokitions, but in higher primates it is much convohited and 

 clearly circumscribed. The relatively small, irregular and non-convoluted 

 nuclei of this group may be considered as primitive, since a comparative 

 study of mammalia, or even of the primates, shows a distinct tendency for 

 the dentate nucleus to become more indefinite in its outline and pattern, the 

 lowxr the animal's position in the scale. Thus, a dentate nucleus with little 

 or no convolution belongs to an animal whose cerebellar function is limited 

 insofar as it does not regulate a complex series of highly skilled acts, but is 

 organized for the more simple muscular reactions, such as seen in the 



