652 MR FRANK J. COLE ON THE 



We are now in a position to describe in order the branches of the facial proper. 

 These are : — 



( 1 ) Dorsal sensory branch (wanting). 



(2) Pharyngeal or visceral ( = palatine). 



(3) Pra>branchial ( = chorda tympani — see Literature) 



(4) Post-branchial ( = B + C above). 



| Spir 



acle wanting.* 



=>• 



(2) Palatine. — Pierces the cartilage of the cranium (see figs. 1 and 3), and runs 

 obliquely through it on to the external wall of the pharynx. It then courses forwards 

 and downwards, giving off a few pharyngeal branches to the roof of the mouth on its 

 way down, and finally passes (accompanied by its fellow of the opposite side) between 

 and ventral to the two nasal sacks, to be distributed to the teeth of the upper jaw — curving 

 slightly backwards to do this. (The teeth are inserted somewhat deeply into the jaw.) 



(3) Chorda tympani. — My reasons for considering the prse-branchial division of the 

 Vllth of fishes to be the homologue of the chorda tympani of mammals are stated in 

 the discussion of the Literature. The chorda of Chimsera, like the palatine, pierces the 

 cartilage of the cranium, and, running obliquely through it, reaches the external wall of 

 the pharynx. Arrived there, it courses straight down towards the lower jaw, giving off 

 several pharyngeal branches anteriorly and posteriorly. At about half-way down, it re- 

 ceives an anastomosing branch from the facial proper B (see below). At the lower jaw 

 it divides into several bundles, of which two are distinguishable as being of larger size. 

 The smaller bundles are mainly distributed to the outer wall of the pharynx, but the 

 two larger ones, after edging the lower jaw, dip under it, and are continued on to the 

 inner wall of the pharynx, where they break up and are distributed to the ventral portion 

 of the pharynx just inside the aperture of the mouth, as far as the mid- ventral line. 



(4a) Post-branchial Bt — This divides into two branches, the larger of which itself 

 divides into two. We thus get three nerves as follows : — 



(a) = Portion of " Ramus opercularis." This is the main branch, and both (b) and (c) 

 spring from it. 



(b) Anastomoses with the chorda tympani. 



(c) To the extensor of the hyoid arch. 



(a) First of all gives off (b), and then dips down and runs under the divisions of the 

 hyomandibular lettered A C D above. Coursing almost straight downwards, but 

 slightly forwards, it reaches the inner face of the muscle supplied by the post-branchial 

 C, hence lying internal to the latter, but in front of it. After this point it has a triple 

 distribution, of which one is the branch c. The other two are as follows : one passes on 

 to the internal face of the muscle supplied by post-branchial C, and this plexus is given 



* I believe a minute spiracle, such as, for example, that in Lamna cornubica, could be demonstrated in Chimmra 

 if the necessary material were forthcoming. 



t See above. Refers to the second of the four divisions of the hyomandibular. 



