THK CKANIAL NEEVES. 



383 



II. The optic or second cranial nerve will be considered in 

 the section dealing with the development of the eye, p. 387. 



Fig. 154. — The brain of an adult Babbit from the ventral surface. The 

 greater part of the left temporal lobe has been sliced oil horizontally. 

 The planes of the three semicircular canals of the left side are indicated 

 by the thiclc lines surrounding the floccular lobe of the cerebellum. 

 (From Marshall and Hurst.) x 2. 



CC, eras cerebri. CG-, corpus geniculatum. D, descending cornu of left lateral 

 ventricle. H, bippocampus major. LF, floccular lobe of cerebellum. LL, lateral lobe 

 of cerebdlum. OC, optic chiasma. OT, optic tract. P, pituitary body. PV, pons 

 Varolii. S A, anterior vertical semicircular canal. SH, horizontal semicircular canal. 

 SP, posterior vertical semicircular canal. T, temporal lobe of cerebral hemisphere. 



I, olfactor y lob e, with roots of olfactory nerves. II, optic nerve. Ill, third nerve or 

 motor oculi. rV", fourth nerve. "V, trigeminal nerve. "VI, sixth nerve or abducens. 

 VII, facial nerve. VIII, auditory nerve. IX, glosso-pharyngeal nerve. X, pneumo- 

 gastric nerve. XI, spinal accessory nei-ve. XII, liypoglossal neiTe. 



Ill, IV, and VI. The third, fourth, and sixth cranial nerves. 



There are no exact observations recorded on the development of 



