GENERAL PHYSIOLOGY. 57 



companying cuts may serve to refresh the memory. 



(Fig 12) 

 j. Operation. To make a gastrocnemius "muscle nerve prep 



aration." 



(1) Make, with scissors, a circular cutaneous incision 

 around the tarsus, corresponding with the lower end 

 of cut B. Make a longitudinal cutaneous incision, 

 beginning at the margin of the circular incision where 

 it crosses the external aspect of the tarsus, carry it 

 along the tibia, along the course of the biceps femo 

 ris muscle, over the pyriformis to the posterior end 



FIG. 12. 

 FIG. 12. Showing the muscles of the frog's thigh and leg. 



of the urostyle, along the whole extent of the uros- 

 -tyle. From the posterior end of the urostyle make 

 an incision posteriorly and ventrally, for 1 or 2 cm. 

 Grasp the free margin of the skin at the point of 

 the circular incision and with a quick traction 

 toward the head of the frog the skin will be re- 

 moved from the whole field of operation. 

 (2) Pass a point of the fine scissors under the glisten- 

 ing tendon of the biceps femoris where it is inserted 



