550 



HYPOPHYSECTOMY AND EARLY DEVELOPMENT 



RANA PIPIENS 



RANA PIPENS 



HYPOPHYSEAL INVAGINATION 



HYPOPHYSEAL 

 INVAGINATION 



STOMODEAL CLEFT 



STAGE 19 



STAGE 17 



HYPOPHYSEAL ANLAGE 



HYPOPHYSECTOMIZED 

 AT STAGE 18 



CONTROL 



HYPOPHYSECTOIY 

 (Causing stunting and failure to develop pigment) 



