THE CEREBRAL HEMISPHERES 151 



man, where further specialization is probably still 

 going on. For this reason Elliot Smith many years 

 ago proposed to call the somatic cortex neopallium. 

 Kappers calls the pyriform cortex palaeopallium and 

 the hippocampal cortex archipallium. In this work 

 the entire olfactory cortex is called archipallium, for 

 the hippocampal and pyriform cortex seem to be 

 genetically and functionally related. 



Obenchain (1925, p. 218) calls in question the 

 current belief that the hippocampus reaches its 

 "maximum development" in lower mammals. If we 

 take into account, not mass but internal structural 

 complexity of the hippocampus, it seems more prob- 

 able that the differentiation of the neopallium and 

 of the nobler cortical functions in higher mammals 

 is correlated with elaboration rather than reduction 

 of hippocampal structure and function in primates. 



Of the subcortical parts, the septum (Fig. ^^, a. 

 parol.) is about as in reptiles. Ventrally of the septum 

 there is an enormous olfactory tubercle (tub. ol.) 

 which is intimately related with the head of the 

 caudate nucleus and probably serves the muzzle re- 

 flexes of feeding reactions. The corpus striatum is as 

 already described in chapter vi. 



The arrangement of the thalamic nuclei which 

 send projection fibers to the cortex in a primitive 

 mammal is shown diagrammatically in Figure 34, and 

 here it will be noticed, as Elliot Smith (1910) has 

 pointed out, that the arrangement of the correspond- 



