204 Journal of Comparative Neurology. 



apart the commissure is of course very short. The combined 

 trunks pass forward to innervate the mucous membrane of the 

 roof of the mouth and upper lip. The third main ramus of the 

 ophthalmicus lies at the dorso-mesal angle of the nasal passage 

 for the entire length of the latter. It first sends a small twig 

 up through a foramen in the dorsal lamella of the internasal 

 plate, which courses forward beside of the naso-lachrymal duct 

 and finally ends in the skin above the nostril. Farther for- 

 ward it sends another twig through a similar foramen which 

 passes directly dorsad to blend with the ramus frontalis {c.f.), 

 as previously described. Near the tip of the snout the re- 

 mainder of this third ramus passes through another foramen 

 and to the skin in company with the terminal filaments of the 

 r. frontalis. 



The pathetic nerve (tr.) is the smallest of the cranial nerves, 

 containing at its origin only about 30 fibres. It originates at 

 the usual point on the dorsal surface of the brain, leaves the 

 cranium through a foramen in the parietal bone and then 

 continues forward between this bone and the m. tem- 

 poralis to the cephalic end of the latter. It then turns lat- 

 laterally and comes into relation with the ventral division of the 

 first branch of the ramus ophthalmicus (*). The details of this 

 relation seem not to be constant even on opposite sides of the 

 same animal. In the specimen figured on Plates XIX and XX 

 these relations are as follows. Between the m. levator bulbi 

 and the anastomosis of the dorsal and ventral ramuli of this 

 division, the patheticus joins the dorsal ramulus, blends with it, 

 but immediately separates again and joins the ventral division, 

 within which it passes cephalad a short distance. Having again 

 separated it passes directly forward to the m. obliquus superior. 

 It is probable that in course of this plexiform union with 

 the fifth nerve it derives a considerable number of fibres 

 from the latter, for upon entering its muscle it contains nearly 

 twice as many fibres as when leaving the brain. The patheticus 

 was not found as a separate nerve, either in Salamandra or in 

 Pipa, though it is distinct in the frog [3], in Necturus maculosus 



