DEVELOPMENT OF THE CEREBRAL CORTEX 



111 



border of the lenticular nucleus nearly to the level of the superior 

 horn of the lateral ventricle, separating the lenticular nucleus 

 from the mass of the corona radiata which is contiguous to the 

 cortex and which is thickly strewn with migrating neuroblasts. 

 This pale zone is sharply defined externally by a more or less 

 compact line of neuroblasts which in horizontal sections would 



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Fig. 2 Transverse section, right hemisphere, of a new-born child, just ante- 

 rior to the temporal pole. Enlarged 2 X. CC, corpus callosum; CIA., cross- 

 cut bundles of the anterior limb of the internal capsule; /., island of Reil; LN., 

 lenticular nucleus; A/'C, caudate nucleus; SP., septum pellucidum. 



probably represent a second layer of the 'Ubergangschicht.' The 

 wall of the ventricle covering the mesial surface of the caudate 

 nucleus is actively producing neuroblasts, while the opposite 

 wall of the ventricle is much less active although not in a state 

 of rest. In this brain the blood vessels are much engorged (prob- 

 ably due to asphyxiation) and many of those in the direct track 



