MAMMALIA. 



697 



quadrupeds : for the most part, indeed, the pupillary aperture is 

 round, as it is in Man ; but in Ruminants, and many other Her- 

 bivora, it is transversely oblong. In the Cats (Felida), that hunt 

 in the gloom, and consequently require every ray of light that can 

 be made available, the pupil is a long vertical fissure ; but this 

 only obtains among the smaller genera, for in those Feline Car- 

 nivora that surpass the Ocelot in size, such as the Leopard, the 

 Lion, and the Tiger, the pupil again assumes a round form. 



(810.) The eyes of Mammalia are lodged in bony orbits, as in 

 the oviparous Vertebrata, and in like manner are supported in 

 their movements by a quantity of semifluid fat, with which the 

 orbital cavities are filled up. In Man, as in Birds, Reptiles, and 

 Fishes, six muscles are appropriated to the movements of each 

 eye-ball, viz. four recti and two obliqui. The four recti mus- 

 cles have the Fig.3-23. 

 same disposi- 

 tion in Mam- 

 malia as in 

 Birds ; that is, 

 they arise from 

 the margin of 

 the optic fora- 

 men, and run 

 forward to be 

 inserted oppo- 

 site to each 

 other upon the 



superior, 



infe- 



rior, and late- 

 ral surfaces of 



the sclerotic coat. The inferior oblique likewise offers a similar 

 arrangement in all the Vertebrata, arising from the margin of the 

 internal wall of the orbit, and running outwards to be attached to 

 the external surface of the globe of the eye. But the superior 

 oblique, in the class before us, takes a very peculiar course. Aris- 

 ing like the rest, it passes forward to the upper and inner margin 

 of the orbit, where its tendon is reflected over a little cartilaginous 

 pulley (fig. 323, c), and turns back again to be inserted into the 

 external and posterior aspect of the eye-ball. 



(811.) In addition to the six muscles appointed for the 

 movements of the eye in MAN and the QUADUUMANA, other 



