<U THE ANATOMY OF THE UoRSE. 



having been removed, it should be placed on a table, and the cut 

 muscles connected with it may be completely cut away after they 

 have been identified. In doing this, a better opportunity will be 

 afforded to observe accurately the insertion of each muscle. In remov- 

 ing the lower portion of the biceps, particular care must be taken 

 not to cut the external popliteal and external saphenous nerves, 

 which are included between it and the outer licad of the gastrocnemius 

 (Plate 18). 



Surface-marking. — The bones of the leg are clothed by muscles 

 except at the inner side of the limb, where the tibia is subcutaneous. 

 This unprotected area of bone corresponds to the shin in man. The 

 superficial muscles of the region (see Plates 17 and 18) form promi- 

 nences more or less distinct, especially in the neighbourhood of the hock, 

 where the various tendons stand out distinctly during the movements 

 of the living animal. 



Position. — In the further dissection of the limb, it may be placed on a 

 clean table, and laid on either side as may be convenient ; or a cord may 

 be passed round the femur, and the limb suspended at such a height as 

 just to permit the hoof to come into contact with the table. This latter 

 method has the advantage of keeping the jjart clean ; and while 

 dissection is being carried on, the leg may be steadied in any position by 

 an assistant. 



Directions. — An incision through the skin is to be canned down the 

 middle line of the limb on its inner side, and terminated a few inches 

 below the hock, where a circular incision may be carried round the 

 limb. The whole of the skin above the circular incision is then to be 

 removed, and the cutaneous nerves and vessels of the region are to be 

 examined. 



The Internal Saphena Vein. On the inner side of the leg, above 

 the hock, two venous branches will be seen to converge and unite to 

 form the internal saphena vein, Avhich is continued up the leg to the 

 thigh, where it has already been dissected. The vessels by whose union 

 the main vein is formed, are the upward continuations of the internal 

 and external metatarsal veins. Slender branches of the saphena ai'tery 

 accompany these veins. 



The External Saphena Vein, This vessel begins at the hock, where 

 it communicates with the internal saphena vein, and with the posterior 

 tibial vein. It ascends at the outer side of the gastrocnemius tendon, 

 and, passing between that muscle and the bice])s, it empties itself into 

 the femoro-popliteal vein. 



Cutaneous Nerves. 1. The ramifications of the internal .'saphenous 

 nerve cover the inside of the leg, and descend over the inside of the 



