!)H 



THE HORSE. 



We are cf course unable to ascertain when the horse experiences eithel 

 of these kinds of indistinct vision, nor are we able to offer any remedy for 

 them: but noliiing can be more certain than that his sight is frequently 

 very imperfect from one of these causes. There is a shying, often the 

 result of cowardice or playfulness, or want of work ; but at otiier times 

 proving, beyond contradiction, a defect of sight. A horse will manifestly 

 mistake the nature of the object before him ; he will run against that 

 which he should have seen : or he will be terrified by a tree or bird, which 

 should not liavc caused alarm. 



This defect of sight is more dangerous than blindness. A blind horse 

 will resign himself to the guidance of his rider or driver; but against the 

 nusconception and starting of a shying horse there is no defence. That 

 horses grow shy as they grow old, no one accustomed to them will deny ; 

 and no intelligent person will be slow in attributing it to the right cause — 

 a decay in the organ of vision, — a loss of convexity in the eye, lessening 

 the convergency of the rays, and throwing the perfect image beyond, and 

 not on the retina. There is a striking difference in the convexity of the 

 cornea in the coll and the old horse ; and both of them, probably, may 

 shy from opposite causes ; the one from a cornea too prominent, and the 

 other from one too flat. We do not think that, in the usual examination 

 of the horse previous to purchase, sufficient attention is paid to the con- 

 vexity of the cornea. 



The remedy for siiying will be considered when we speak of the vices 

 of horses. 



There is a provision yet wanting. The horse has a very extended field 

 of view, but man)'- persons are not perhaps aware how little of it he can 

 command at a time. There is not one of our readers who can make out a 

 single line of our treatise without changing the direction of the eye. It is 

 curious to follow the motion of the eyes of a rapid reader. To move the 

 iiead and neck in order to adapt the eye to the whole scene before us, 

 would be awkward and fatiguing, and Nature has adopted a simpler and 

 better method. She has given no fewer than seven muscles to the horse, to 

 turn this little but important organ ; and that they might act with sufficient 

 power and quickness, no less than six nerves are directed to the muscles of 

 the eye generally, or to particular muscles ; and the eye rests on a mass of 

 fat, that it may be turned with little exertion of power, and without friction. 



MUSCLES OF THE EYE. 



There are four straight muscles, three of which are represented in our cm, 

 rf, e, and f, rising from the back of the orbit, and inserted into the ball of 

 the eye, opposite to each other, and at equal distances from each other. 

 One, d, runs to the upper part of the eye, just behind the transparent and 

 visible portion of it, and its ofTice is clearly to raise the eye. When it «;on 



