ORIGINS OF THE CEREBRAL CORTEX 85 



The reptilian type of cortex is preserved in some 

 parts of the olfactory field (archipallium) of lower 





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 */'^ 





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13 14 



Fig. 13. — Archlpallial cerebral cortex of the opossum from the 

 middle of the pyriform lobe {a. pir. med. of Fig. 2,^y p. 154). From an 

 unpublished drawing kindly furnished by Dr. P. A. Gray. Magnifica- 

 tion, 50 diameters. 



Fig. 14. — Neopallial cerebral cortex of the opossum from the area 

 parietalis or somesthetic-motor cortex {a. par. of Fig. 2)^, p. 154). From 

 an unpublished drawing kindly furnished by Dr. P. A. Gray. Magnifica- 

 tion, 50 diameters. 



mammals with very little change. Figure 12 illus- 

 trates an arrangement of cells in the extreme anterior 



