THE FOOT IN HEALTH AND DISEASE 107 



with the sensitive laminge on the pedal-bone, but the 

 bone itself is densely packed with minute openings for the 

 passage of small blood-vessels into its interior, augmented 

 by larger vessels of supply. 



The coronet, as previously stated, consists of a dense 

 band of tissue encircling the top of the hoof, supplied 

 with blood by the coronary artery. 



The sensitive structures of the foot comprise the sensi- 

 tive laminae, the sensitive sole, and the sensitive frog. 

 We have already referred to the sensitive laminae, so that 

 it only remains to deal with the sensitive sole and the 

 sensitive frog. The first-named forms a velvety tissue 

 spread over the lower surface of the pedal-bone, and from 

 which the horny sole is formed. The sensitive frog is 

 composed of fibro-elastic tissue, which confers upon it a 

 degree of expansion when the foot is on the ground. 

 There is no expansion of the wall at the toe, and very 

 little at the quarters, but at the heels it is present in a 

 limited degree. 



Two tendons pass down the back of the foot, viz. the 

 flexor pedes perforans and perforates, the former being 

 attached to the lower surface of the pedal-bone, and the 

 latter to a small bone known as the navicular or shuttle- 

 bone, which is in juxtaposition to the pedal-bone. In 

 addition to this we have ligaments and nerves distributed 

 to the sensitive structures enclosed within the foot. 



The bones of the foot are entirely enclosed by the hoof, 

 and occupy a very sheltered position, so that one would 

 expect injuries in connection with these to be excessively 

 rare, but such is not the case. In fact, the writer has seen 

 apparently trifling accidents result in fracture of either 

 the pedal-bone or the navicular-bone as revealed by an 

 after-death examination of the parts concerned. The 

 pedal-bone, also known as the cofhn-bone, the navicular- 

 bone, and the second phalanx, or the os coronce, are 

 the bones embedded within the hoof, and two of these 

 present many special interesting features, to which, in a 



