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 thegymno- 

 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; /-A", 

 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 



