THE RABBIT. 3 2 9 



situated within and dorsal to the auriculo-ventricular 

 aperture. 



XXXIX. Dissect away the skin from the side of the 

 head, and make out : 



331. The masseter, a large mass of muscle covering 

 the posterior half of the mandible. 



It arises from the lower edge of the jugal arch, and is inserted into 

 the lower border of the mandibular ramus. 



332. The muscular branches of the seventh or facial 

 nerve, passing from behind forwards over the outer surface 

 of the masseter. 



Traced backwards, these nerves are seen to spring from a single trunk 

 which makes its exit through the stylo-mastoid foramen ( 55). 



333. The parotid (salivary) gland, a soft, irregular, 

 pinkish mass, situated just in front of and below the 

 external ear. 



Its fine duct (Stenson's- duct) passes forwards from its anterior 

 edge, along with the branches of the seventh nerve, and in front 

 of the masseter muscle dips inwards, to open into the interior of the 

 mouth. 



334. Trie infraorbital (salivary) gland, a large lobu- 

 lated mass lying in the antero-inferior region of the orbit, 

 partly outwards and partly within the cavity. 



Its duct passes downwards from its inferior edge, to open into the 

 cavity of the mouth. 



XL. 1 Cut away, with bone-forceps, the supraorbital 

 process of the frontal ( 47), working from behind 

 forwards, and making out : 



335. The superior oblique muscle of the eye, arising 



1 The following sections ( 335353) cannot conveniently be 

 worked out in a specimen from which the brain has been removed, 

 unless that operation has been conducted with very great care. 



