FORM AND ACTION OF THE FOOT. 27 



hills, the liorse may vary his action to suit the circum- 

 stances, and then we have the exception, which proves 

 the rule — then we have sometimes the heel, sometimes 

 the toe brought first to the ground. 



At the time when the foot first touches the ground, 

 the leg is extended forward and the pastern is in the 

 same oblique position to the shank as when a liorse is 

 standing. This obliquity of the pastern is another safe- 

 guard against concussion, and it renders impossible the 

 first contact with the ground at any point other than at 

 the heel. As the leg becomes straightened, the weight 

 of the body is imposed upon the foot, but the greatest 

 strain arrives just before the toe leaves the ground, for 

 then there is not only weight to sustain, but the friction 

 to be borne which results from the toe being the fulcrum 

 upon which falls the whole effect of the muscular effort 

 necessary to raise and carry forward the body of the 

 animal. The front part of the foot is structurally vrell 

 adapted for its use. It presents the thickest and strong- 

 est part of the horny covering; and, as an inside basis, it 

 hp.s the unyielding coffin bone. Thus we have at the 

 too strength and rigidity; at the heels, strength and 

 elasticity. 



Another important point in the action of the foot is 

 implied by the question — does it expand when weight is 

 thrown on it? The principles of horse-shoeing require 

 that this question should be answered. There are those 

 who say that the foot does not alternately expand and 

 retract as weight is placed upon or removed from it. 

 There are others who assert that the expansion of the 

 foot is an important natural function that must be pro- 

 vided for in any system of shoeing. It is agreed by most 

 observers that at the upper border of the hoof, more par- 

 ticularly at the heels, expansion does occur. It is when 

 we come to the lower border of the foot that the state- 

 ments are most conflicting. Ordinary measurements 

 taken at this part with calipers or by tracings on paper 

 of the foot when raised from the ground and when rest- 

 ing upon it, show no variations in the width of the foot. 

 These methods of measurement are not sufficiently 



