46 THE FROG 



In the thigh, commencing at the lateral margin: 



290. At the proximal end the small iliacus externus. 

 Origin from ilium: insertion on femur. At its distal 

 end it is obscured by the caput posticum of the 

 triceps (280). 



291. From the urostyle another small muscle, the 

 pyriformis, extends to the head of the femur. 



292. Mesial of the caput posticum, the slender ilio- 

 fibularis. Origin from ilium: insertion on tibio- 

 fibula. 



293. The large muscle at the mesial margin is the semi- 

 membranosus. Origin from ischium: insertion on 

 tibio-fibula. 



In the shank, in addition to the plantar longus (289) 

 and tibialis anticus longus (285), note 



294. the peroneus, between the two just noted. Origin 

 from femur: insertion on fibia and fibulare. 



Cut through the sartorius (281) and identify: 



295. The adductor longus, a narrow muscle covered by 

 the sartorius. Origin from the ilium: insertion with 

 that of adductor magnus (282). 



296. The iliacus intemus may now be identified. It 

 extends from the ventral border of the ilium to the 

 femur. 



Cut through the gracilis major (283) and identify 



297. the semitendinosus, a delicate muscle with two 

 heads, covered by the gracilis major. Origin from 

 ischium: insertion on tibio-fibulare. 



The deeper muscles of the thigh, six in number, as well as 

 the muscles of the foot, are omitted. 



Drawing 23. Draw the dorsal musculature of the 

 hind leg (x2). 



