l] the frog. 107 



the 5th and 7th, and passing behind the auditory 



capsule, much as do the 5 th and 7 th in front of 



it 



a. The \oth or pneumogastric {vagus); its cut 



end will alone be seen. Soon after leaving the 



skull it bears a large ganglion {g. trimci vagi). 



y8. The 9//^ or glossopharyngeal ; it arises im- 

 mediately in front of a, and is largely con- 

 fluent with the above-named ganglion. It 

 is commissurally connected with the posterior 

 branch of the 7 th {comniissiii'a ad facialem). 

 Its distribution has been studied (§ i. a). 



g. The 8//^ or auditory ; arising from the medulla 

 along with the 7th, part of which it appears 

 to be. Dissect to its level and trace it into the 

 auditory capsule. 



5. The synpathdic system. 



Dissect from the ventral aspect as before, but 

 leave the aorta, the cut end of the cccliaco-me- 

 senteric artery and the base of the large intestine 

 with the bladder, in place. On raising the aorta 

 the sympathetic will be found immediately beneath 

 (dorsal to) it. 



a. The viain tru7ik of the sympathetic ; paired and 

 longitudinal, accompanying the arches and trunk 

 of the aorta. 



h. The spla7ichnic nerve ; arising from a at the point 

 of junction of the aortic arches and accompanying 

 the coeliaco-mesenteric artery. 



c. The sympathetic ganglia; enlargements on <2, vari- 

 able in size and number ; usually one for each 



