252 Anatomy of the Rabbit. 



(d) The sixth cranial, or abducent nerve (n. abducens), is 

 distributed to the rectus lateralis, and to the retractor oculi. 



(e) The ophthalmic nerve (n. ophthalmicus), the first division 

 of the fifth cranial, or trigeminal nerve (n. trigeminus), 

 accompanies the inferior ophthalmic artery on the medial 

 wall of the 'orbit. It gives off a lacrimal nerve, which 

 passes upward through the posterior foramen of the supra- 

 orbital process, and then passing forward a short distance 

 divides in two parts. One of these, the frontal nerve, 

 leaves the orbit through the anterior supraorbital foramen, 

 while the other, the nasociliary nerve, is partly distributed 

 to the anterior portion of the orbit, and is connected with the 

 minute ciliary ganglion lying on the optic nerve, forming its 

 sensory root. Its chief portion leaves the orbit through 

 the ethmoidal foramen of the orbital portion of the frontal 

 bone as the ethmoidal nerve. 



The lacrimal, frontal and nasociliary nerves appear as 

 separate structures in the orbit, their origin being deep. 



(f) The branches of the maxillary nerve (n. maxillaris), the 

 second division of the trigeminus, traverse the ventral por- 

 tion of the orbit passing forward in company with the 

 internal maxillary artery. They include the spheno- 

 palatine nerve (n. sphenopalatinus) and the infraorbital 

 nerve (n. infraorbi talis). The latter gives off superior 

 alveolar branches co the upper teeth, passing forward 

 through the infraorbital groove and foramen to the face. 



The connections of the sphenopalatine nerve may be examined 

 by first dividing both nerves at the posterior angle of the orbit; then 

 separating the slender sphenopalatine nerve from the ventral sur- 

 face of the cord and turning the principal, infraorbital portion 

 forward. A third nerve, the nerve of the pterygoid canal, should 

 remain intact on the orbital wall. If the infraorbital nerve alone 

 is divided, the sphenopalatine nerve will be found on the surface 

 of the bone below the nerve of the pterygoid canal, from which 

 it may be distinguished by its lighter coloration. 



The sphenopalatine nerve is continued forward as the anterior 

 (major) palatine nerve, which passes through the pterygopalatine 

 canal to the posterior portion of the hard palate, but is also con- 



