MUSCLES AND PARTS CONNECTED WITH THE EYE 175 



in this, another muscle, d d, called the retractor, is 

 added ; it arises from the edge of the foramen, through 

 which the optic-nerve enters the orbit. The use of 

 this muscle is to support the eye generally, or when 

 it is suddenly called into great action, and aided by 

 the straight muscles, it draws the eye back out of the 

 reach of danger, and in the act of drawing it back it 

 forces the haw to protrude in the manner already 

 described, as an additional defence. The cornea, i, 

 is the only visible part of the eyeball of a horse, or at 

 least it should be ; and it is said that where much 

 white is seen, that it is an indication of bad temper. 

 The pupil, ;, in the horse differs in form from that of 

 all other animals. It is of an elongated, oblong, 

 ovate form, and placed transversely, as represented in 

 fig. 4, Plate in. 



The eye is a very important organ in the horse. 

 It ought to be large and rather prominent ; the 

 eyelid should be fine and thin. This thinness is for 

 the purpose of preventing pressure, and at the same 

 time to give more extensive and easy motion. 



The horse is devoid of eyebrows, and the eye- 

 lashes are singularly arranged. The rows of hairs 

 are longest and most numerous on the upper lid, and 

 especially towards the outer or temporal corner, 

 because the light falls on the eye from above ; and 

 as he stands, especially when he is grazing, as well as 

 from the lateral situation of the eyes, the greater 

 portion of the light, the attacks of insects, and the 

 trickling down of moisture, is chiefly from the outside. 

 Towards the inner corner of the eye there are hardly 

 any eyelashes, because there is little or no danger 

 from below, and as little light is thrown from below, 

 the eyelashes are thin and short. While horses are 

 grazing, insects may find their way to the eye towards 



