The coffin bone or third digit is peculiar in the horse. Both in structure 

 and economy there is a close analogy between this bone in the horse and 

 the double form of the same bone in the ox ; but the resemblance is only 

 partial, each bone being fitted for the special purpose for which it is wanted. 

 The cloven-footed animal moves with astonishing security over granite rocks, 

 where the horse is less adapted to venture. This fact is shown also in the 

 different kinds of goat and deer, and in a lesser degree in the ox. All 

 cloven-footed animals are endowed with wonderful security of foothold, but 

 they lack the elasticity needed to carry weight, as well as the graceful movement 

 of the horse, with his ample security of footing over hill and dale. In such 

 places the noble creature finds sustenance for life, and here his special 

 powers of speed and endurance are required. The coffin bone has much of 

 the form of the hoof in its exterior aspect, and when the lateral cartilage, 

 with the other structures attached to it, is seen in connection the whole 

 structure is similar in its outward form to that of the hoof (Cramgee). On 



reference to the accompanying picture of the coffin bone, it is seen to 

 resemble in its leading features the external form of the hoof, one chief 

 difference being found to consist in the former being fully a fourth shorter than 

 the inner cavity of the latter. When, however, this wonderfully- 

 constructed bone, of which we append a drawing, is furnished with the 

 cartilages, ligaments, tendons, and all the other important structures, of 

 which it constitutes the centre, it assumes the form and becomes the 

 counterpart of the hoof. 



The horse's hoof is not only to be regarded as a covering for the 

 protection of the sensitive structures from injury. The hoof has its specially 

 assigned place in the whole economy of the foot, and each separate 

 component part must be looked upon as an essential constituent of the 

 whole organisation. The hoof forms an integral part of the foot, and those 

 animals that lack it, though amply protected as they are, cannot sustain 

 weight and undergo the same fatigue on the same spots, as those which 

 possess it. Of all creatures gifted with the hoof, the horse is tlic superior 

 (Gamgee). 



The inner face of the hoof presents over its entire extent while parallel 

 leaves, which dovetail with the prolongations or lamin:i} of sensitive vascular 

 tissues. The hoof has three parts — the wall, the sole, and the frog ; and 

 the horn composing these parts differs in composition. That of the wall is 



