24 THE AH.MY HORSE IN ACCIDENT AND DISEASE. 



of the extensor pedis a short distance below the hock. Action, to 

 assist the extensor pedis. 



The tendon of the peroneus is cut in the operation for string halt. 



The jlexor metatarsi is divided into two portions— a muscular and 



a tendinous. The tendinous part is a strong pearl-white cord, situ- 

 ated between the muscular portion and the extensor pedis. It com- 

 mences at the lower extremity of the femur, and terminates in two 

 branches — a large one inserted in front of the upper extremity of the 

 cannon bone and a small one deviating outward to reach the front 

 surface of the cuboid bone. The fleshy portion originates on the 

 front face of the tibia and is inserted by two tendons, one in the head 

 of the large metatarsal bone, the other in the small cuneiform on the 

 inner side of the hock. Action, to flex the hock. 



The Jlexor pedis perforatus of the hind leg originates at the back 

 and lower part of the femur. Its fleshy portion extends about 

 halfway down the tibia, then becomes tendinous, and passes over 

 the point of the hock, continues down the back of the leg, and is 

 attached in the same manner as the perforatus of the front leg. 

 Action, to extend the hock and to flex the fetlock and pastern. 



The gastrocnemius externus has a double origin at the lower and 

 back part of the femur and is attached to the point of the hock. At 

 the back part of the leg the tendon of this muscle becomes closely 

 associated with the tendon of the flexor pedis perforatus, the two 

 forming the tendon of Achilles, or hamstring. 



The jlexor pedis perforans of the fund leg originates at the upper 

 and back portion of the tibia. Above the hock it becomes tendinous 

 and passing down over the inner and back side of the hock is at- 

 tached to the os pedis in the same manner as the perforans of the 

 front limb. Action, to extend the hock and to flex the joints below. 



Wide muscles are attached to other structures by broad bands of 

 strong white tissue instead of by tendons. 



The panniculus carnosus (fly shaker) is a wide flat muscle situated 

 on the inner surface of the skin and covering most of the neck, sides 

 of the chest, and belly. Action, to shake the skin. 



The principal muscles of the back, loins, and haunches are the 

 longissimus dorsi, gluteus externus, gluteus maximus, and gluteus 

 interims. 



The longissimus dorsi is situated on the upper part of the back and 

 loins, and is the largest and most powerful muscle in the body. 

 occupying the space on either side of the dorsal and lumbar spines. 

 Is broad and fleshy at its origin in the loins and becomes narrower as 

 it proceeds forward. It is attached to the front part of the pelvis 

 (ilium), f iist two bones of the sacrum, all of the lumbar and dorsal 

 vertebra', the external surface of the last fifteen or sixteen ribs, and 

 to the last three or four cervical vertebrae. Action: It is brought 



