286 



G. R, DE BEER 



front of the head generally were growing forward and the 

 hypophysis caught tight between the brain and the gut-roof 

 were prevented from joining in this forward movement and 



Text-fig. 27. 



Amia calva. Slightly later stage than the preceding, the hypo- 

 physis is beginning to lose connexion with its point of origin. 



Text-fig. 28. 



AdO 



Amia calva. The same as Text-fig. 27, higher magnification. 



SO comes to lie relatively farther back. The demarcation 

 between hypophysis and gut-roof is again hard to pick out, 

 but the restriction of large yolk-granules to the latter is plain. 

 As development proceeds the brain and the front of the head 

 generally seems to have grown and extended anteriorly. But 



