126 



THE STRUCTURE OF MAN 



early period of development, reached exactly to that point at 

 which the coccygeal gland is found later, and that, as already 



FIG. 77. BRAIN OF A DOG-FISH (Scyllum caiiicida). 



A, dorsal ; B, ventral ; C, side view ; 6.0., bulbus olfactorius ; ep., pineal gland cut short ; 

 f.b., fore-brain ; f.r., fossa rhomboidalis ; h.b., hind-brain (cerebellum) ; hp., hypo- 

 physis ; i.f., iufuudibulum ; i to x, first to the tenth cranial nerves (the thalamen- 

 cephalon and the fossa rhomboidalis are in life covered by epithelium (plexus 

 chorioidei), not delineated ; the ventral vagus roots are omitted from Fig. B) ; 

 md., medulla oblongata ; m.h., mid-brain (optic lobes) ; sc., saccus vasculosus ; 

 t.o., tractus olfactorius. 



mentioned, all the important variations at the caudal end of the 

 trunk are primarily associated with degeneration of the spinal 



