NERVOUS SYSTEM. VERTEBRATA. 



193 



Thus the small size of the cerebral hemispheres which 

 leave the greater part of the corpora quadrigemina exposed ; 

 the high degree of macrosmatism in an arboreal animal; 

 the prominence of the hippocampus; the small dimensions 

 of the corpus callosuin; and the smallness and primitive 

 simplicity of the cerebellum, all point to the lowly status 

 of this peculiar mammal, not far removed from the 

 Insectivora. 



Fig. 67. (Nat. size.) 



.OLF.BULB. 



ig. 68. (Nat. size.) 



RHIN.F. ACOU.TUE 



Fig. 69. (Nat. size.) 



SULC.CALC. 



SULC.ROS. 



CLF.BULB.- 



Fig. 70. (Nat. size.) 



The very definite series of deep sulci on the cerebral 

 hemisphere, however, at once separates Galeopithecus from 

 the Insectivores proper. 



On the mesial surface there is a relatively small and 

 very obliquely-placed corpus callosum. The large fascia 

 dentata is, to a great extent, exposed on the surface 

 (fig- 69). 



There is a deep calcarine (splenial) sulcus ; beginning, as 

 is usual, near the termination of the rhinal fissure and 

 pursuing a course approximately horizontally forward. Its 



VOL. ii. o 



