58 THE ANATOMY OF THE HORSE. 



In the thigh it lies in front of the gracilis. About the middle of their 

 line of apposition the saphena vessels and nerves emerge, but below that 

 point the muscles are adherent to each other. It is inserted into the 

 internal straight ligament of the patella. 



Action. — To adduct and flex the hip-joint. To a slight extent it may 

 also rotate the limb inwards at the stifle. 



The Gracilis (Plate 12). This muscle does not possess the slender 

 character from which it is named in human anatomy. It is a large, 

 somewhat four-sided mass, forming the greater part of what is termed 

 the Jlat of the thigh. A linear depression seen on the surface of the 

 muscle when it is cleaned, is often mistaken by students for the line of 

 separation between it and the sai-torius. It arises from the lower face 

 of the pubis and ischium close to the symphysis, and it is here united 

 to its fellow of the opposite side. Inferiorly it has a broad flat tendon, 

 united in front to that of the sartorius. It is inserted with the sartorius 

 into the internal straight ligament of the patella, and into a line on the 

 tibia between its anterior and internal tuberosities. The posterior edge 

 of its tendon is continuous with the deep ftiscia of the leg. A large 

 branch from the external pudic veins traverses the muscle near its 

 origin, and opens into the femoral vein. 



Action. — To adduct the hip, and rotate the limb inwards. 



Directions. — The two preceding muscles are to be carefully cut across 

 about their middle, and turned upwards and downwards. On reflecting 

 the proximal half of the gracilis, branches of the obtui-ator nerve and 

 deep femoral artery will be seen penetrating its deep face ; and, in the 

 same way, twigs from the saphena nerve will be found entering the 

 sartorius. The deep inguinal glands are to be removed, and the 

 femoral vessels and anterior crural nei've are to be dissected. 



The Femoral Artery (Plate 13) is the main arterial trunk for the 

 supply of the hind limb. It is the direct continuation of the external 

 iliac, the brim of the pelvis being selected as the arbitrary line of 

 division between the two vessels ; and, in like manner, it is directly con- 

 tinued by the popliteal artery, the vessel changing its name when it 

 passes between the two heads of the gastrocnemius muscle. The lower 

 third of the vessel, however, will not be exposed till the next stage of 

 the dissection. The part of the vessel now seen begins at the pelvic 

 brim, where it is seen issuing from beneath Poupart's ligament. It 

 there rests on the common termination of the iliacus and psoas magnus, 

 having the sartorius in front and the pectineus behind. In the thigh it 

 descends obliquely downwards and backwards, resting first on the com- 

 mon termination of the iliacus and psoas magnus, and then on the 

 vastus internus. It has the sartorius in front ; while posteriorly it is 

 related first to the pectineus, and then to the adductor parvus. In this 

 course it corresponds to the interstice between the gracilis and sartorius 



