122 STRONG. [Vol. X. 



proceeds cephalad and, turning ectad, becomes continuous with 

 a branch of the R. maxillaris V as already described (p. in). 

 The remainder, much diminished, passes on cephalad and 

 becomes continuous with a branch of the R. ophthalmicus V 

 as already described (p. io8). 



From the nature of these curious anastomoses, it is dif^cult 

 to determine, exactly where the Facialis ends and the Tri- 

 geminus begins. Their significance lies, I believe, in the fact 

 that the R. palatinus VII, on the one hand, and the Rr. oph- 

 thalmicus and maxillaris V, on the other, innervate territories 

 morphologically distinct, and that in the region where these 

 fusions occur these two territories meet. In other words, they 

 occur just about on the boundary between the pharynx and the 

 stomodaeum. Of the part becoming continuous with the R. 

 ophthalmicus, it is not improbable that all which continues 

 cephalad beyond this commissure, though indicated as partly 

 composed of each element in the chart {g.v.)y belongs to the 

 Trigeminus, and that the same is true of a considerable portion 

 of that which is caudad of this point of fusion. Along its 

 course this branch gives off a considerable number of fibres 

 which form a plexus around the openings of the posterior nares 

 into the pharynx. As a line drawn through the anterior part 

 Oi these openings would indicate the line of demarcation 

 between the stomodaeum and pharynx, it is not impossible that 

 these fibres represent the last fibres from the R. palatinus 

 proper, and that the remainder of the branch consists entirely 

 of fibres coming caudad from the R. ophthalmicus. A still 

 more minute study of this portion, however, would be neces- 

 sary to determine this point exactly, from observation, and the 

 possibility must also be admitted that the regions innervated 

 by fibres from the R. ophthalmicus V and the R. palatinus 

 VII, respectively, overlap to some extent. This, however, 

 would not impair the general validity of the view here put 

 forward as to the significance of these anastomoses. 



What has been said above applies also to the anastomosis 

 between the R. palatinus VII and the R. maxillaris V. Here 

 again the exact delimitation of the R. palatinus cannot be 

 determined. 



