THE TELENCEPHALON IN CYCLOSTOMES Bll 
between the limbs of the U. In this position it enters into rela- 
tions with the lateral olfactory nucleus which lead to the formation 
of the pyriform lobe as an olfacto-somatic correlation center 
(cortex). Within the somatic primordium there develop also com- 
plex correlation systems between the cutaneous, musculo-sensory, 
auditory and visual fiber tracts which probably reach this center at 
an early stage in the phylogeny (see 710 c¢, and ’11 a). This com- 
plex correlating organ is the general cortex. As it develops it 
pushes in between the primordium hippocampi and the pyriform 
lobe, assuming the characteristic postion of the general cortex 
in mammals. The expansion of the general cortex pushes the 
hippocampal formation to the medio-dorsal border of the hemis- 
phere and the pyriform lobe down to the ventral surface. 
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