The Muscles and Their Worlc. 23 



the front of the forearm, one originates at the head of 

 the bone of the forearm and is inserted on the front sur- 

 face of the upper pastern bone ; the other commences on 

 the bone of the arm just above the elbow joint and ends 

 on the upper and front part of the coffin bone. Those 

 muscles which bend the fetlock, pastern and coffin joints 

 and aid in bending the knee, originate on the back part 

 of the forearm ; a short distance above the knee they 

 become tendinous (sinew-like) and form what are known 

 as the ' ' back tendons, ' ' or, as they are sometimes called, 

 the cords or sinews; at the back of the knee they pass 

 through a sheath formed by the trapezium and binding 

 (annular) ligament, thence down the back of the cannon 

 bone. The one lying in front (the flexor pedis perfo- 

 rans) lies just behind the suspensory ligament, goes over 

 the sesamoids, little round bones at the back of the fet- 

 lock, down the back of the pastern until it passes over 

 the shuttle bone (os naviculare), which has a smooth, 

 pulley-like surface, and is then inserted (fastened) into 

 the under side of the coffin bone. It is of interest to 

 know that this muscle is re-inforced just below the knee 

 by what is known as the check ligament. When dis- 

 cussing the joints, structures called ligaments were men- 

 tioned and their functions described; in connection with 

 the muscular tissues, there are what are known as sus- 

 pensory and check ligaments, whose offices are to render 

 assistance in a greater or less degree to muscles. The 

 suspensory ligaments are very powerful, and if the back 

 tendons were severed would prevent the fetlock sinking 

 to the ground. The suspensory ligament lies right behind 

 the cannon and between the two splint bones, it originates 



