184 PEOCEEDINGS OF THE AMERICAN ACADEMY. 



(b) Ramus maxillaris trigemini emerges from the Gasserian gan- 

 glion in the same transverse plane with r. biiccalis and r. ophthalmicus 

 superficialis VII., and the three appear (Fig. 2) as one nerve for a short 

 distance, as they pass laterad and cephalad between m. temporalis and 

 m. masseter. While ramus ophthalmicus superficialis VII. separates from 

 the others and curves mesiad, rami maxillaris V. and buccalis VII. pass 

 cephalad along the dorso-lateral surface of the masseter muscle. In 

 many of the specimens examined the two appear like one nerve, but the 

 difference in the size and distribution of the fibres was always noticeable, 

 and in the series of sagittal sections used for reconstructions they w^re 

 clearly separate. R. maxillaris ( V. mx.) gives off a small general 

 cutaneous branch, not shown in the drawings, to the dorsum immedi- 

 ately after leaving the ganglion, and its final distribution is to the skin 

 of the cheek. It does not anastomose with ramus palatinus VII., as is 

 the case in the tadpole of Rana (Strong). 



(c) Ramus mandibularis trigemini ( V. md.) leaves the ganglion 

 directly below ramus maxillaris, passes ventro-laterad, gives off first a 

 branch ( F)8) to m. masseter, next, two more small branches (not 

 figured) to the same muscle, and then a fourth ( Fy), which runs 

 dorsad to m. temporalis. In the same transverse plane with Vy there 

 arises a cutaneous branch ( V8), which runs ventro-laterad and is dis- 

 tributed to the skin posterior to the angle of the jaw. It comes into 

 very close connection with the more anterior branch of ramus man- 

 dibularis externus VII. ; in some series of sections it even appears to 

 anastomose with this branch of VII. ; but other sections show conclu- 

 sively that it does not. Another general cutaneous branch ( Ve) is 

 given off from ramus mandibularis V. to the angle of the jaw, a small 

 twig from it turning caudad; the main branch (Ve), however, runs 

 forward, close above ramus mandibularis externus VII. to the skin of 

 the lower lip. A division of the main nerve into nearly equal parts 

 ( V. md. i. and V. md. ex.) soon occurs. A musculo-cutaneous branch 

 (V. md. z'.), Gaupp's ramus mandibularis internus V., passes ventrad 

 between os dentale and Meckel's cartilage to the lower side of the jaw, 

 where it innervates m. mylohyoideus and the skin superficial to it. 

 The other branch ( V. md. ex.), which is purely cutaneous, remains on the 

 upper side of the jaw and is distributed to the skin of the lower lip. It 

 corresponds to Gaupp's ramus mandibularis externus V. 



