PAPIO C^'NOCEPHALUS 



301 



the optic chiasm and optic tracts and caudally by the convergent libers 

 of the cerebral peduncles. In this space is lodged the tuber cinereum, bearing 

 the attachment of the infundibular stalk and the mammillarv bodies. 



FIG. 143. DORSAL SURFACE OF BRAIN STEM, PAPIO CVNOCEPHALUS. 



[Actual Length 46 mm.] 



Kev to Diagram, d. med. fissure, Dorsomedian Fissure; d. med. septum, Dorsomedian Septum; inf. 

 COLLICULUS, Inferior CoUicuIus; sup. cerebr. ped., Superior Cerebellar Peduncle; sup. colliculus, 

 Superior CoIIicuius; tub. trigem., Tuberculum Trigemini; 7TH N., Seventh Nerve. 



A well-delined median groove along the ventral surface of the pons 

 marks the position of the basilar artery. The pons itself has attained more 

 prominence in baboon than in the lower primates, and this may be taken as 

 indicative of extensions in the pallio-pontile connection, in turn signifying 

 an increase in the cerebral cortex. Since it is by means of the pons that ulti- 

 mate connection between the cerebral hemisphere and the cerebellum is 

 established, functionally, this connection as it is at present understood 

 concerns itselt w ith the coordination of the extremities. It is believed that 



