DISEASES OF THE EYE. 179 



what is known all over the country as " hooks." The dis- 

 ease is variously called " bone hooks " and " fatty hooks." 

 Yet there are many among the masses who doubt the exist- 

 ence of " hooks," and the question is often asked whether 

 horses do really have them. To this query only one reply 

 is possible. Ko hook, or hooks, or any thing else, grows in 

 the eye that does not belong there. If people were better 

 informed concerning the structure and uses of the haw, they 

 would not fall into such errors in regard to the " hooks." 



The haw — or "washer," as it is sometimes called — is a 

 little, triangular-shaped cartilage, lying just within the inner 

 corner of the eye, where ]^ature has provided a cavity, in 

 which it rests when not in use. Being thus stored away, 

 only a small portion of it can be seen when the eye is in 

 health. Its shape is exactly adapted to the convexity of the 

 eye. Like other cartilages, its texture is tough and gristly. 

 It is also very elastic. 



The haw serves as a sort of scoop, to pass quickly over the 

 eye and throw off any offending substances which may have 

 lodged upon the ball, such as dust, hay-seed, flies, and gnats. 

 Motion is given it, not directly by muscular action, and yet, 

 at the will of the horse, most perfectly. The arrangement 

 by which this is effected is curious and admirable indeed. 

 The orbit — the cavity in which the eye is placed — is plenti- 

 fully supplied with fatty deposits, which enable the organ to 

 turn in all directions without friction; and these deposits 

 are most abundant in the part back of the eye, especially 

 toward its inner corner. Powerful muscles surround the eye. 

 These the horse contracts when any disagreeable substance 

 alights upon the eye-ball ; by a mechanism almost peculiar 

 to the horse, the eye is drawn back in its socket ; the fatty 

 deposits near the inner corner are pressed down upon the 

 haw with such force that it is thrust out, and, darting with 

 lightning-like velocity over the surface of the eye-ball, gathei» 

 up the offending particles of dirt, or whatever foreign body 

 is to be removed. Then the muscles relax ; the eye and its 

 fatty deposits resume their original arrangement; and the 





