Some Observations on the Hypophysis of 

 Petromyzon and of Amia. 



By 

 G. R. de Beer, B.A., B.Sc, 



Demonstrator in the Department of Zoology and Comparative Anatomy, 

 University Museum, Oxford. 



I. Petromyzon. 



Introduction. 

 The hypophysis of Petromyzon has been the object of 

 research of many observers, more indeed than will be referred 

 to in this paper since complete bibUographies are to be found 

 elsewhere, and it might almost seem as though any further 

 work on the same subject could not but be repetition. It 

 seemed to me, however, when considering the problems 

 presented by the hypophysis in the light of more recent 



