230 Journal of Comparative Neurology. 



able variation in the manner of origin from the geniculate gang- 

 lion. It leaves the ganglion by two divisions of about equal 

 size. One of these passes dorsally, and the other ventrally of 

 the m. retractor bulbi. Beyond the muscle the two divisions 

 of the nerve fuse into a common trunk which does not differ in 

 any other respect from the typical palatine nerve. 



y. — The Ramus Palatinus Caudalis. 



The r. palatinus caudalis arises from the distal portion of 

 the geniculate ganglion. It may penetrate the cartilage into the 

 roof of the mouth only a little way from the foramen of the r. 

 palatinus. On the other hand, it may be fused with the hyo- 

 mandibular trunk nearly to the distal end of the foramen. In 

 one case it leaves this trunk near the opening of the foramen 

 and passes caudad in a foramen of its own in the cartilage of the 

 latero-ventral border of the ear-capsule. It emerges from this 

 foramen at the anterior margin of the fenestra ovalis. In other 

 cases, two nerves penetrate into the roof of the mouth by dis- 

 tinct foramina and function, apparently, as the r. palatinus 

 caudalis. 



Soon after the nerve emerges from its foramen it unites 

 with the second ramus of the ninth nerve to form Jacobson's 

 anastomosis. From this fusion the enlarged nerve passes 

 cephalad in the roof of the mouth about to the transverse level 

 of the optic foramen and in a position approximately ventral of 

 the r. ophthalmicus profundus V. It sometimes receives twigs 

 from the r. palatinus. 



8. — Accessory Trigemimal Twigs. 



Besides the main rami of the fifth nerve there are, in some 

 specimens, two small caudad nerves which arise independently 

 from the Gasserian ganglion or from the general cutaneous 

 component of the infra-orbital trunk soon after it leaves the 

 ganglion. When they do not; appear independently they are 

 probably incorporated into some of the branches of infra-orbital 

 nerve. I distinguish them as the first ^n^ second accessory twigs 

 of the trigeminus (not figured). 



The first accessory twig arises from the Gasserian ganglion 



