126 THE BRAIN OF REPTILES 



they show a transverse fissure which divides the two bodies 

 into four parts, corresponding to the ' corpora quadrigemina' 



Fin. /JR. -Brain and Cranial Norvc=» of ]3oa Constrictor. (Rymcr Jones, after Swan.) 

 «, Cereljral lobes ; b, ojitic lobes with transverse depression ; c, cerebellum ; d, mem- 

 brane of the nose ; 1, olfactory norve ; 2, optic nerve ; 3, third, or common oculo- 

 muscular nerve ; 4, fourth, or trochlear nerve to the superior oblique muscle of the 

 eye ; 5, first tnink of the fifth ; 6, se ond trunk of the fifth ; 7, third trunk of the 

 fifth ; S, hard portion of the seventh nerve ; 9, auditory nerve ; 10, glosso-pharyngeal 

 nerve ; 11, trunk of the vagus nerve; VI, nintli nerve. Tlic last three nerves are 

 intimately connected with one another, and with 13, a sympathetic ganglion 



