156 



COMPARATIVE MORPHOLOGY OF VERTEBRATES. 



is visible from above. The infundibulum and hypophysis are well developed but 

 the saccus vasculosus and inferior lobes are smaller than in fishes. In the gymno- 

 phiones, owing to the pontal flexure the hypophysis is carried back beneath the 

 medulla oblongata. Both paraphysis and pinealis are present, the latter not reach- 



FIG. 158. Dorsal and ventral views and sagittal section of brain of Desmognathus, after 

 Fish, a, anterior commissure and rudimentary corpus callosum; c, cerebrum; cl, cere- 

 bellum; e, epiphysis; h, hypophysis; i, infundibulum; oc, optic chiasma; ol, optic lobes; p, 

 paraphysis; pc, posterior commissure; cp, chorioidplexuses ; sc, superior commissure; I-X, 

 nerves. 



ing the cranial roof except in the anura, the conditions in this group having already 

 been mentioned (p. 147). The cerebellum is very small, a mere transverse fold 

 on the anterior border of the fossa rhomboidea. The gymnophione brain is notice- 

 able for the pontal flexure already alluded to, which carries the hemispheres so far 



