58 



CEREBRAL DEVELOPMENT 



the homologies, we may trace in those of the central line, 

 Fig. 20. 



i 



CKANIAL BUCKIiEB OF DIPTERUS. 



from the snout to the nape, what seem to be the representa- 

 tives of the frontal, parietal, and occipital bones, — the pari^ 



Fig. 21. 



BASE OF CRANIUM OF DITTERUS. 



