359 



h)g the navicular, by a wide expansion of its fibers. It is the function 

 of this tendon to flex the coffin bone and with it the horny box. 



The flexor pedis perforaius^ or superficial flexor of the foot, follows 

 the course of the precedinf? tendon and is attached to the middleof the 

 anlde. The function of this tendon is to flex the foot at the fetlock. 



The extensor pedis runs down in front of the leg, is attached on the 

 most prominent point of the coffin bone, and has for function the 

 straightening of the bones of the ankle and foot. 



The bones, ligaments, and tendons are covered by a loose connective 

 tissue, which gives a symmetry to the parts by filling up and rounding 

 ofl", and all are protected by the skin and hoof. 



The slcin of the fetlock and ankle is generally characterized by its 

 thickness and the length of its hairs, especially around the hind parts 

 of the fetlock joint in certain breeds of horses. The most important 

 part of this envelope is that known as the coronary band. 



The coronary hand is that portion of the skin which secretes the horn 

 by which the wall of the hoof is made. This horn much resembles the 

 nail which grows on. the fingers and toes of man. It is composed of 

 hollow, cylindrical tubes, extending from the coronary band to the 

 lower border of the hoof, which are held together by a tenacious opaque 

 matter. (Plate xxix, Fig. 1.) 



The lioof is a box of horn, consisting of a wall, sole, and frog, and 

 contains, besides the cofiiu, navicular and part of the small pastern 

 bones, the sensitive laminae, plantar cushion and the lateral cartilages. 

 (Plate XXX, Fig. 4.) 



The sole of the foot incloses the box on the ground surface, is shaped 

 like the circumference of the foot, except that a V-shaped opening is 

 left behind for the reception of the frog, and is concave on the lower 

 surface. The sole is produced by the velvety tissue, a thin membrauce 

 covering the irlautar cushion and other soft tissues beneath the coffin 

 bone. The horn of the sole differs from the horn of the wall, in that 

 its tubes are not straight, and from the fact that it scales off in pieces 

 over the whole surface. 



T he/ro</is a triangular shaped body, divided into two equal parts by 

 a deep fissure, extending from its apex in front to the base. It fills the 

 triangular space in the sole to which it is intimately attached by its bor- 

 ders. The horn of the frog is produced iu the same manner as the sole, 

 but it differs from both the wall and sole, in that the horn is soft, moist, 

 and elastic to a remarkable degree. It is the function of the frog to 

 destroy shock and to prevent slipping. 



The sensitive htminw are thin plates of soft tissue, covering the en- 

 tire anterior surface of the coffin bone. They are present in great num- 

 bers, and by fitting into corresponding grooves on the inner surface of 

 the horn of the wall the union of the soft and horny tissues is made 

 comi)lete. (Plate xxix. Fig. 1.) 



The plantar cushionis a thick pad of fibrous tissue, placed behind and 

 under the navicular and coffin bones, and resting on the sole and frog, 



