THE INFRA-ORBITAL TRUNK. 189 



r. maxillaris {uix. V) in the strict sense. The former is 

 composed wholly or nearly so of the very coarse lateralis 

 fibres and is a portion of the r. buccalis. 



The r. maxillaris, after separation from these buccalis 

 fibres, contributes to them a general cutaneous bundle 

 and gives off for the remainder of its coarse numerous 

 small twigs for the skin of the side of the head in front of 

 the eye and for the outer surface of the upper jaw. There 

 are also given off large branches (apparently communis 

 fibres) for the mucous lining of the jaw and the edges of 

 the upper lip. These regions abound in taste buds and 

 there is no doubt that these are supplied by this nerve, 

 for there is no other obvious nerve supply. Other 

 branches, doubtless also communis fibres, were traced 

 into the dentary canal of the premaxillary bone and 

 apparently innervate its teeth. 



Stannius (p. 42) mentions these fibres for the mucosa 

 of the mouth and also in several cases anastomoses with 

 terminal twigs of the r. palatinus, which seem to be 

 absent here. It is evidently a portion of this communis 

 element in the r. maxillaris which corresponds to the 

 nerve supply for the maxillary barblet of siluroids (Pol- 

 lard), as suggested by AUis ('97, p. 635). 



The remainder of the infra-orbital trunk, comprising 

 lateralis and general cutaneous fibres, runs up along the 

 inner and front walls of the orbit and then passes farther 

 mesad and continues cephalad under the parethmoid bone 

 along the inner side of the lower end of the olfactory 

 fossa and under the posterior nasal aperture. It turns 

 dorsad along the cephalic face of the lateral part of the 

 parethmoid and laterally of the olfactory sac. While still 

 lying close to the mucous membrane of the olfactory sac, 

 which is not in this region sensor}^ it breaks up into 



