CHAPTER II. 



DISSECTION OF THE POSTERIOE LIMB. 



In the male subject, the dissection of the perinseum must be completed 

 before the dissector of the hind limb can begin his operations. 



THE INNER ASPECT OF THE THIGH. 



Position. — The animal should be placed on the middle line of its back, 

 and its hind limbs should be drawn forcibly upwards and outwards by 

 ropes running over pulleys fixed to the ceiling. This is the position 

 most convenient for allowing the dissection of both hind limbs to be 

 pursued at the same time. If only one limb is being dissected, the rope 

 may be unfastened from that limb, and the body allowed to incline to 

 the same side, as in Plate 12. 



Surface-marking. — The internal saphena vein ascends on the inner 

 aspect of the thigh ; and a few inches below the upper limit of the region, 

 it dips in between the sartorius and gracilis muscles. Pressure at this 

 point in the living animal will produce distension of the vessel, and 

 render its course much more evident. Venesection is sometimes per- 

 formed on this vessel. Above the point where the before-mentioned 

 vessel disappears from view, the deep inguinal lymphatic glands are 

 situated in the interstice between the sartorius and gracilis muscles. 

 They here cover the femoral artery, and may be very distinctly felt in a 

 case oi lymphangitis, or "weed." 



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

 middle line of the thigh, and terminated a few inches below the level of 

 the stifle-joint. Here another incision is to be made across the inner 

 aspect of the limb, from its anterior to its posterior border. These 

 incisions, together with those already made in the dissection of the 

 perinseum, will enable the dissector to reflect the skin as an anterior and 

 a posterior flap. The student should then dissect the internal saphena 

 vein with its accompanying artery and nerve, and the cutaneous nerves 

 at the forepart of the region, which are derived from the lumbar nerves, 

 Thereafter the surface of the sartorius and gracilis is to be cleaned, and 

 these muscles are to be examined. 



The Internal Saphena Vein (Plate 12). This is a large vesse' 



