52 LANDMARKS MEDICAL AND SURGICAL. 



of a hen's egg, is between the tendon of the inner head of 

 the gastrocnemius and the tendon of the semimembranosus, 

 just where they rub one against the other. The bursa is from 

 one and a half to two inches long. When enlarged, it makes 

 a swelling on the inner side of the popliteal space, which 

 bulges and becomes tense when the knee is extended, and 

 I'icc versa. I examined 150 bodies with a view to ascertain 

 how often this bursa communicates with the synovial mem- 

 brane of the knee. There was a communication about once 

 in five instances. This should make us cautious in interfering 

 too roughly with the bursa when enlarged. 



113. Popliteal artery. The popliteal artery can be felt 

 beating and can be compressed against the back of the femur, 

 close to which it lies. But pressure, sufficient to stop the 

 blood, should be firm, and should be made against the bone 

 nearer to the inner than the outer hamstrings. The line of 

 the artery corresponds with the middle of the ham. It lies 

 under cover of the fleshy belly of the semimembranosus, and 

 the outer border of this muscle is the guide to it. An incision 

 down the middle of the ham would fall in with the vessel just 

 above the condyles. 



114. Peroneal nerve. The peroneal nerve runs parallel 

 with and close to the inner border of the tendon of the biceps. 

 It can be felt in thin persons. There is a risk of dividing it 

 in tenotomy of the biceps, unless the knife be carefully intro- 

 duced from within outwards. Below the knee the nerve can 

 be felt close to the fibula just below the head, and when 

 pressed upon in this situation causes a sensation to run down 

 its branches to the foot. 



THE LEG AND ANKLE. 



115. Bony points. The tubercle of the tibia (for the 

 attachment of the ligamentum patellae), the sharp front edge 

 called the shin, and the broad flat subcutaneous surface of the 

 bone can be felt all the way down. The inner edge can be felt 

 too, but not so plainly. The lower third is the narrowest 

 part of the bone and the most frequent seat of fracture. 



