Herrick, Cranial Nerves of Amblystonia. 203 



ward it lies between this muscle and the m. temporalis, where it 

 gives off a large branch whose peripheral relations are very pe- 

 culiar. It first separates into two divisions. The dorsal divis- 

 ion enters the m. rectus superior a little farther cephalad than 

 the point where the ramus of the oculomotor nerve enters this 

 muscle. Within the body of the muscle it divides and the two 

 parts leave the muscle on opposite sides with undiminished vol- 

 ume. The smaller part is directed mesally and terminates in 

 the skin of the dorsum. The larger part is directed laterally, 

 penetrates the sclerotic coat of the eye-ball, and curves around 

 to the dorsal side of the eye-ball, there to enter the ciliary pro- 

 cess. It is therefore to be regarded as the ciliary netve (cil.) 

 The ventral division of the first branch of the r. ophthalmicus 

 also separates into two ramuli which penetrate, passing mesally, 

 the m. levator bulbi, beyond which they anastomose. In this 

 region they establish relations with the fourth nerve (*), as de- 

 scribed below. They subsequently break up into numerous 

 fine branchlets to be distributed to the skin of the dorsum and 

 upper eye lid. 



Farther forward the r. ophthalmicus lies above the m. 

 rectus internus and between the m. levator bulbi and the bulb of 

 the eye. Here it sends another branch dorso-mesad taking 

 about the same course as the ventral division of the branch last 

 described, and at the cephalic end of the orbital cavity divides 

 into three main rami. The first of these passes around to the 

 lateral aspect of the nasal cavity and there breaks up into five 

 branchlets which are distributed along with the terminal ramuli 

 of the r. maxillaris to the skin of the upper lip and the region 

 about the nostril. The second ramus passes for a short distance 

 along the mesal aspect of the m. obliquus inferior, then passes 

 ventrad along the mesal wall of the nasal passage to the ventro- 

 mesal angle of the latter. Here it communicates by means of a 

 broad commissure with the palatine nerve (com. p.) One of 

 these nerves lies immediately beneath, the other immediately 

 above the tip of the ventral lamella of the internasal plate. 

 The commissural fibres pass around this tip and as these two 

 nerves lie in this region only a small fraction of a millimeter 



