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 
7 
Kia. 77.—BRAIN OF A DoG-FISH (Scyllum canicula). 
A, dorsal ; B, ventral; C, side view ; 0.0., bulbus olfactorius ; ep., pineal gland cut short ; 
J.b., fore-brain ; f.7., fossa rhomboidalis ; h.0., hind-brain (cerebellum) ; hp., hypo- 
physis ; 7.4, infundibulum ; 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) ; 
m.d., medulla oblongata; m.h., mid-brain (optic lobes); sc., saccus vasculosus ; 
t.0., tractus olfactorius. 
mentioned, all the important variations at the caudal end of the. 
trunk are primarily associated with degeneration of the spinal 
