hypophysis of petromyzon and amia 



Text-fig. 9. 



Fb ^.ch/ 



267 



0/ 



Imm 



S.ih. 

 Petromyzon planeri. Embryo 35 mm. lon^ 



Text-fig. 10. 



O.ch 



S.ih. 



Petromyzon planeri. The same embryo highly magnified. 

 Differentiation of the glandular elements. No trace of a hypo- 

 physia) cavity. 



