268 THE LOWER PRIMATES 



THE NUCLEUS GLOBOSUS 



The nucleus globosus chiefly represents the central or vermal portions 

 of the cerebelhim. Functionally the vermis is more rigidly fixed and responds 

 but little to the progressive expansions of behavior. It supphes coordinative 

 control to the axial muscles which show considerably less adaptive variation 

 than the appendicular muscles. These axial muscles determine primordial 

 postural patterns of the body. From the phyletic standpoint their coordina- 

 tive control is palcostatic. It has been present from the beginning of verte- 

 brate organization when trunkal movements were the preeminent requisites 

 of locomotion. The expansion of such trunkal movements, as behavior 

 becomes progressively more complicated, is relatively small in comparison with 

 that of limb movements. Hence the nucleus globosus shows no marked degree 

 of development concomitant with the cerebellar lobes or the cerebral hemi- 

 spheres. In this respect it differs from the dentate nucleus. 



COMPARISON OF NUCLEUS DENTATUS AND NUCLEUS GLOBOSUS 

 IN LOWER PRIMATES 



In general, the dentate nucleus appears most prominent in such animals 

 as are possessed of the most highly diflerentiated forelimbs. These nuclear 

 relations when applied to the lemur, tarsier, marmoset and mycetes are made 

 clear in the planimetric and longitudinal coefficients as shown in the tables: 



Planimetric Coefficients of the Nucleus Dentatus and Nucleus Globosus 

 IN Lemur, Tarsier, Marmoset and Mycetes 



