210 MANUAL OF MODERN FARRIERY. 



jrelatinoiis fluid, resembling the white of at egg. It fills 

 about tliree-fourths of the globe of the eye, and extends 

 from the posterior part as far forward as the ciliary liga- 

 ment. ' 

 q. The aqueous, or water-like humour which fills the space 

 between the cornea and the crystalline lens. 



It is by means of this humour that the cornea is preserved 

 m its rounded form. A small portion of it is behind 

 the iris. 



r. The retina, or fine net-like expansion of the optic-nerve, 

 which is spread over the whole of the choroides, as far as 

 the lens. 



.9. The optic-nerve, or nerve of sight. 



(. The conjunctiva, or that membrane which covers the for- 

 part of the eye, and which lines the lids, and even extends to 

 the transparent portion of it. It is transparent, and transmits 

 colour to the parts beneath. It is very liable to "uiflamma- 

 tion, during which the vessels of the lining of ihe lids will 

 become gorged with blood, and present an intensely red 

 appearance, wliich extends itself to tliob-e vessels in the 

 white of the eye, which will also become completely covered 

 with blood, and will ultimately render the cornea clouded 

 and opaque. This membrane is the seat of almost all the 

 diseases of the eye ; many of which too frequently terminate 

 in total blindness.' 



A defect of sight in the horse is more dangerous than 

 total blindness, for this reason, that one with a defect of 

 sight will start and shy at every object which he meets with 

 upon a road, and the rider may be thrown off when he least 

 expects it ; while a horse that is quite blind will generally 

 resign himself to the guidance of his rider or driver. 



THE TEETH AND THEIR DEVELOPMENT. 



Mastication in the horse is performed in two ways, namely, 

 by a champing motion, and also a grinding motion. 



At 0, plate iii. fig. 1, is the masseter-muscle, which is of 



