CEREBRAL NERVES 



165 



to the muscles and skin of the lower jaw. The trigeminal 

 is a mixed nerve. 



The sixth or abducent (Fig. 49, VI) is a very small 

 motor nerve arising from the ventral aspect of the 



5.sp 



FIG. 53. Dissection of the head and anteriorpart of the body of the Frog from the 

 left side, to show the distribution of the fifth, seventh, ninth, and tenth cerebral 

 nerves, as well as of the hypoglossal and part of the sympathetic, (x i.) 

 Ao. systemic arch ; br. pi. brachial plexus ; co. columella ; D. ao. dorsal aorta ; 

 du. duodenum ; H. heart ; Hy. body of hyoid ; Hy l . anterior, and Hy 2 . posterior 

 horns of hyoid ; L. lung ; N. olfactory sac ; On. orbit ; Put. pulmonary artery ; 

 Sp. A. splanchnic artery ; st. stomach ; Sy. sympathetic ; II. cut end of optic 

 nerve ; v\ ophthalmic, V' 2 . maxillary, and V*. mandibular branch of trigeminal 

 (V) VII 1 palatine, and VIP* hyomandibular branch of facial; IX. glosso- 

 pharyngeal ; X. vagus ; Xcd. cardiac, Xgas. gastric, Xlar. laryngeal, and 

 Xpul. pulmonary branch of vagus ; / Sp. first spinal nerve (hypoglossal) ; 

 2 sp. j sp. second to fifth spinal nerves. (After Howes, slightly modified.) 



bulb, and supplying one of the muscles of the eye-ball 

 called the posterior rectus. 



The seventh or facial nerve (Figs. 49 and 53, VII) 

 arises just behind the fifth and soon joins the Gasserian 

 ganglion. Both it and the sixth leave the skull by the 

 same aperture as the fifth. It divides into two branches, 



