HOMOLOGY OF PITUITARY LOBES 



59 



also attended by a different orientation of the hypophysis 

 lobes. If we take as our starting point the hypophysis of 

 fishes answering as nearly as possible to the basic design, as, 

 for instance, Rhodeus or Leuciscus, the lobus tuberalis is most 

 cranially situated. Then follows the lobus anterior, and 

 behind this the lobus intermedius, while the lobus posterior 

 as composed with the higher vertebrates, does not adjoin the 

 hypophysis at the back, but is situated intra-hypophysially. 

 The lobus intermedius is more prominent in fishes than it is 

 in mammals, where the lobus posterior is larger. As the axis 

 of the hypophysis shifts forward the lobus tuberalis becomes 

 more dorsal (Pseudo pleuronectes, Carassius) and finally 

 comes to lie against the hypothalamus (Zoarces or Catpiodes, 

 Fig. 50B), as in mammals, where the lobus tuberalis sur- 

 rounds the tuber cinereum. In the case of a caudal shift of the 



Fig. 5 I A. 

 Medial sections of the hypophyses of: 



I Petromyzon, 

 II Hippocampus, 



III Anomalops, 



IV Lebistes, 

 V Anguilla, 



VI Leuciscus, 

 VII Rhodeus, 



