78 ZOOTOMY. 



superior and internal recti, over the peduncle of the eye 

 ( 200) and the optic nerve ( 199), under the superior 

 oblique, and finally unites with the dorsal ramus as it 

 perforates the nasal capsule ( 205). 



199. The optic nerve (Fig. 22, //), which, after leaving 

 the skull, passes almost directly outwards to the hinder 

 region of the eye-ball. Its extra-cranial portion is invested 

 with a strongly pigmented sheath. 



200. The ophthalmic peduncle, an irregular stalk of 

 cartilage, articulated at its proximal end with the skull wall 

 behind the optic foramen, and at its distal end with a knob 

 on the sclerotic coat of the eye. 



201. The inferior oblique muscle of the eye, running 

 parallel with the superior oblique, to the antero-inferior 

 region of the eye. 



202. The inferior rectus, arising with the other recti, 

 and passing parallel with the superior rectus to its insertion 

 on the inferior region of the sclerotic. 



203. The remaining course of the third nerve (Fig. 22, 

 ///): after curving round the superior rectus, it passes 

 forwards and sends branches to the inferior rectus (it.r) and 

 inferior oblique (i.o). 



XLIII. Remove successive slices from the nasal cap- 

 sule, until the following structures are brought into 

 view. 



204. The strongly pigmented nasal sac, filling up the 

 cavity of the nasal capsule. 



205. The orbitc-nasal nerve (Fig. 22, V 1 ) which, just 

 before the junction of its two rami, enters the nasal capsule, 

 and divides into two branches, a large one which passes 

 along the outer edge of the rostrum, and a small one, 

 which passes outwards and forwards over the roof of the 

 nasal sac. 



