220 Journal of Comparative Neurology. 



Where the ophthalmicus profundus comes into close re- 

 lation with the m. retractor bulbi it gives off ventrally the in- 

 ferior ciliary nerve (not figured). On the surface of the retractor 

 muscle the inferior ciliary nerve sometimes comes in contact 

 with the sixth nerve, but this relation seems accidental. A little 

 farther along its course, ventrally of the ophthalmicus profundus, 

 it comes in relation with the inferior branch of the oculomotor 

 as described on page 212. From this point the ciliary nerve may 

 continue along the surface of the rectus inferior to the insertion 

 of the muscle, or it may lie entirely apart from this muscle, un- 

 till it approaches the eye-ball. A part of the nerve enters a 

 foramen in the sclera under the insertion of the m. rectus infe- 

 rior, beyond which the fibers could not be definitely traced. The 

 rest of the branch continues laterad between the sclera and the 

 surrounding fascia to the margin of the sclerotic cartilage, and 

 there enters the eye. 



The second branch {0. p. V. 2.) of the ophthalmicus pro- 

 fundus is given off dorsally at about the same level as the first. 

 It passes cephalad dorsally of the main nerve to the margin of 

 the temporalis muscle where it divides. One of the nerves re- 

 sulting from this division is the superior ciliary (not figured). 

 It may come in contact with the superior branch of the third 

 nerve as described on page 6, and then follow the m. rectus 

 superior to the eyeball, or it may pass freely from the point of 

 branching to the insertion of the rectus superior, under which 

 it enters a foramen in the sclera. In some cases, and perhaps 

 as a rule, this division penetrates the m. rectus superior. 



The other division of the second branch of the ophthal- 

 micus profundus is a cutaneous nerve . It turns dorsad around 

 the lateral margin of the m. rectus superior and then cephalad 

 along the dorsal surface of the muscle it inclines dorso-mesiad 

 and divides. The anterior of the two resulting twigs passes to 

 a position mesial of the r. ophthalmicus superficialis VII. It 

 sends a itw fibers cephalad but the larger part of the twig turns 

 caudad to the skin over the cranium near the mid-dorsal line. 

 The other twig of the cutaneous branch passes directly caudad 



