THE RABBIT 



457 



laryngeal and passes backwards beside the main vagus, and 

 a recurrent or inferior laryngeal branch, which loops forward 

 round an artery and runs beside the trachea to the muscles 

 of the larynx ; behind this the vagus passes backwards along 

 the oesophagus ; (3) the cervical sympathetic, lying beside the 

 vagus and depressor; (4) the spinal nerves, of which the 

 third gives a great auricular branch to the ear and 

 the fourth and fifth give off branches which join to form 

 the phrenic nerve to the diaphragm. The vagus bears its 



Kar'iL 



Fig. 333. — A diagram of the ear of a rabbit. 



e.a.m. t External auditory meatus; E-u., Eustachian tube; f.o., 

 fenestra ovalis ; inc., incus; lab., parts of the membranous 

 labyrinth, containing endolymph ; lig., ligaments ; mat., 

 malleus; peril., perilymph; St., stapes; tym., tympanic 

 membrane. 



vagus ganglion just before it gives off the superior laryngeal 

 nerve, and the sympathetic bears near the ends of the neck 

 its two cervical ganglia. 



The sense organs do not differ from those of the frog 

 enough to need special descriptions. Besides 

 the structures we have mentioned in connec- 

 tion with the eye, there must be noticed the 

 lacrymal or tear glands, situated above the outer corner of 

 each eye, as well as Harderian glands corresponding to 

 those of the frog (p. 80). There are no Harderian glands 

 in man. The secretion of the eye glands flows over the 



30 



Sense 

 Organs 



