HOMOLOGY OF PITUITARY LOBES 



57 



Bretschneider and Pelsma made a histological examina- 

 tion of the hypophysis of 19 different vertebrates, i.e., 

 Petromyzon fluviatilis; Polypterus senegalis; Anguilla vul- 

 garis; Zoarces vtviparus; Lophius piscatorius; Anomalops 

 graeffii; Leuciscus rutilus; Rhodeus amarus; Carpiodes car- 

 pio; Lebistes reticulatus; Hippocampus antiquorum; Triton 

 taeniatus; Bufo bufo; Xertopus laevis; Rana ternporaria; 

 Seps chalcides: Gallus dornesticus; Serinus canaria and Felis 

 domestica. They arrived at the following conclusions as 

 regards comparative anatomy. 



The basic structure of the vertebrate hypophysis shows not 

 three but four lobes, i.e., the lobus tuberalis, lobus anterior, 

 lobus intermedius and lobus posterior, which follow from 

 front to back in this order (Fig. 50 A) . There is considerable 



yventr.M 



(T)lob. tuberalis 

 (2) hb. anterior 



thalamus 

 ^recessus infundib. 



lob. posterior 



crar)io- basic 



platy- basic 

 B 



lepto- basic 



Fig. 50. Scheme of the different pituitary types. 



departure from this basic structure, especially in fishes. We 

 have tried to bring some order into this diversity, and have 

 introduced one or two new terms. In this way we were able 

 to distinguish a number of general types having the follow- 

 ing characteristics. 



