532 'Journal of Comparative Neurology and Psychology. 



teriorly to supply the temporal muscle on the top of the head. 

 While this branch to the temporal muscle is passing anteriorly 

 th^re is given off from it a short distance from its origin from the 

 main trunk a small branch which running mesally into the 

 pterygoid muscl^ gives off twigs to the latter and descending 

 applies itself so closely to the outer border of the r. ophthalmicus 

 profundus as to be with difficulty distinguished from it. Leaving 

 the r. oph. prof, nerve at the ventral border of the latter, it runs 

 anteriorly to innervate the two small muscles, previously men- 

 tioned, which have their insertion upon the antorbital cartilage 

 (figs. 5, 13 and 22, jnh.). 



These two muscles appear to have escaped the notice of previous 

 writers. One of these (figs. 4 and 22, rth.) has its origin on the 

 posterior part of the maxillary bone and the anterior part of the 

 pterygoid cartilage. As seen in the illustrations, its action is to 

 depress the antorbital cartilage. From the position of the tip of 

 the latter ventral to the eyeball the contraction of the muscle will 

 bring about a retraction of the eye, or it acts as a retractor bulbi 

 muscle. Its position and origin make such an homologizing not 

 improbable. The other muscle {Ivb.) has its origin on the orbito- 

 sphenoid and parietal bones. Its contraction opposes that of the 

 retractor muscle, or elevates the antorbital cartilage. It is here 

 designated as levator bulbi muscle. As previously noted, the 

 nerve supplying these two muscles sometimes comes into intimate 

 relations with the abducens nerve. But that there is no funda- 

 mental anastomosis between them is shown by the fact that this 

 small branch to the retractor and levator bulbi muscles sometimes 

 arises directly from the gasserian ganglion and passes out of the 

 cranium through the foramen of the oph. prof, nerve and lateral 

 to the latter, thence anteriorly through the pterygoid muscle dorsal 

 and mesal to the oph. prof, without coming in contact with the 

 latter, and nowhere approaching closely to the abducens nerve 

 (fig. 22). 



As the r. mandibularis passes out through the masseter muscle 

 it gives off twigs to the latter. One large branch, composed of 

 motor and general cutaneous fibers, runs for some distance nearly 

 parallel with the main nerve. Its motor fibers finally pass to the 

 anterior part of the masseter muscle; its general cutaneous fibers 

 run as a large branch nearly to the level of the mandible, and a 

 little anterior to the angle of the jaw break up into twigs that run 



