460 CONTRACTION. 



horse, with which it is often hereditary. A good deal also de- 

 pends upon the country — the nature of the soil, and the dryness 

 or humidity of the situation — wherein the animal happens to have 

 been bred or brought up, since that will, in a measure, so influence 

 the quality of the horn as to render it liable to contraction. Horses 

 of the breeds and from the countries I have named, having light 

 bodies to carry, with hoofs of the oblong description, and strong 

 luxuriant fibre, and which possess light and near-the-ground 

 action, may be said to be predisposed to contracted feet. On the 

 other hand, heavy horses — such as are used by agriculturists and 

 brewers, &c., are subject to disease or deformity the opposite 

 of contraction. Thin hoofs, of weak fibre, broad and flat, and 

 such as are sprawl, are prone to disease of laminse, and to 

 become pumice. Colour has been said to harbour some 

 predisposition to contraction. Blaine insists upon the dark 

 chestnut being its favourite subject. The texture and colour of 

 the hair may have an influence over its correlative tissue, the 

 hoof; and certain colours may prevail among light or well-bred 

 horses, or among horses of certain countries. Farther than this 

 I can perceive no connexion between colour of coat and con- 

 traction of hoof. 



The Causes of Contraction, i. e., of pure contraction, 

 are either direct or indirect. I shall consider the latter, as 

 being the more influential, first. In order to render the nature 

 and operation of this set of causes intelligible, it will be neces- 

 sary to premise an observation or two on the physiology of the 

 foot. Made, as this organ is, for the double purpose of sup- 

 porting the weight of the horse's body and moving under it with 

 elasticity or spring enough to ward off concussion, its structure is 

 such as to enable its component parts to possess certain motions, 

 one upon the other, so that the effect of the whole together may 

 be, expansion of the hoof during the imposition of weight and 

 the force of action upon it : retraction of the parts taking place 

 the moment such weight or force of action ceases to be in opera- 

 tion. This property of yielding or expansion it is which, while it 

 answers the purpose of a spring to the animal body, acts counter 

 to that tendency inherent in the hoof, particularly when deficient 



