THE BRAIN. 



145 



The former character is seen most plainly in the Agamae 

 and Ascalabotae (Geckos), the latter in Snakes, Chelonians, 

 and Crocodiles. A knowledge of the anatomy of the skull will 

 help us as regards the external form of the brain of Reptiles, and 



FIG. 120. BRAIN OF Emys europaea. (A, side, B, ventral view.) 



VH, cerebral hemispheres ; Lol. olfactory lobe ; T, temporal lobe ; Inf, infundi- 

 bulum : H, hypophysis : MH, optic lobes ; HH, cerebellum ; NH, medulla 

 oblongata ; B, spinal cord ; /, olfactory, and II, optic nerves ; Tro, optic tract ; 

 Chi, optic chiasma ; ///, oculomotor; IV, trochlear; F 1 F 3 , first, second, 

 and third divisions of the trigeminal, all of which arise from the Gasserian gang- 

 lion, GG : VI. abducent, VII, facial, VIII, auditory, IX, glossopharyngeal, X. 

 vagus, and XI, spinal accessory nerves; I Sp, II Sp, first and second spinal 



the reader is referred to that section of the introduction to the 

 chapter on the skull in which the interorbital narrowing of the cranial 

 cavity is described (p. 57). 



The brain of Lizards and Blindwonns (Anguis) exhibits a far 



L 



