MAMMALIA. 137 



small branches from separate foramina ; the second entirely and immediately joins the 

 large branch of the hard portion proceeding towards the chin, and the rest communicate 

 with some of the branches of this nerve. The principal part of the inferior dental 

 nerve then emerges from the foramen near the chin, and ramifies in the usual manner. 

 The buccal nerve in the calf gives a branch to the external pterygoid muscle ; it then 

 passes over the inner surface of this muscle ; it emerges from underneath the anterior 

 edge of the masseter, and divides into branches, which terminate on the buccinator 

 muscle and the skin of the face, and form considerable communications with branches 

 of the hard portion. The buccal in a great measure supplies the cheek, or that 

 triangular portion situated between the masseter muscle and the corner of the mouth, 

 so that it is larger or smaller in different animals according to the extent of this part. 



The sixth in the monkey arises from the posterior edge of the annular tubercle 

 and the pyramidal body, nearly as in man ; and in the horse and sheep, from the 

 trapezoid body in the groove corresponding with that continued downwards on the 

 outer side of the pyramidal body. It communicates with the sympathetic in the 

 monkey, dog, jaguar, pig, calf, and others ; and in the calf also with the first trunk 

 of the fifth. It terminates in the abducent muscle ; also in the retractor in the 

 porpoise and other animals. 



The character, origin, and distribution of the auditory nerve are nearly the same 

 as in man. It arises from the side of the fourth ventricle and the external portion 

 of the restiform body, and has a slight connection with the involuntary centre. It 

 communicates with the hard portion in the internal auditory meatus ; after its division 

 one portion passes to the base of the cochlea, and sends branches through perforations 

 in the modiolus to the spiral lamina, on which it forms a more fibrous or thready retina 

 than the optic nerve, whilst the rest terminates in the vestibule and the semicircular 

 canals. In the porpoise it is very large on account of the size of the cochlea. 



The hard portion of the seventh in the horse and ox arises from the tract of the 

 larger portion of the intermediate layer of the external region as it passes through 

 the annular tubercle, more externally it is connected with the trapezoid body, and 

 in the porpoise proceeds from the prominence occupied by the trapezoid body and 



