114 ELEMENTARY BIOLOGY. [CHAP. 



8. The ^th cranial nerve (n. patheticus] ; seen, on 

 slightly pulling the eye-ball outwards, skirting 

 the inner wall of the orbit to reach the su- 

 perior oblique muscle. 



e. The $rd cranial nerve (oculomotor}. A branch 

 of this may be seen breaking up in the 

 superior rectus muscle, if that be cut across 

 near its point of attachment to the eye-ball 

 and turned back. 



. The lower eyelid follow it forwards, it will be 

 found to be continuous with a strong tendon 

 which passes through a loop immediately ex- 

 ternal to the superior oblique muscle. 



b. Ventral aspect. Turn the head over and pin 

 down ventral surface uppermost ; remove the 

 entire lower jaw and floor of the mouth, and 

 dissect off the mucous membrane of its roof 

 with care. 



a. The levator bulbi muscle ; a sheet-like mass 

 underlying (overlying as seen) the whole eye- 

 ball; its fibres pass obliquely outwards and 

 backwards. 



Compare a transverse section such as is de- 

 scribed at Sect. C. 3. The fibres will be found 

 to pass between the upper jaw and the in- 

 ternal dorsal wall of the orbit. 



/3. The inferior oblique ; a small muscle passing 

 upwards and inwards between the antero- 

 internal face of the eye-ball and the orbit. 



y. The Harderian gland ; a nodular mass im- 

 mediately behind ft, interposed between the 

 eye-ball and orbit. 



