of the Leg of the Crocodile. 327 



On removing the skin and dissecting away the fat, the mus- 

 cles shown in PI. XVI, fig. A are exposed. 



1. M. gluteus maxinius [b). Origin : from central half of 

 the ilio-ischiadic line. Insertion : into the fascia outside and 

 above the knee-joint. This is a broad Hat muscle, and straps 

 down the tendon of the rectus femoris in its passage over the 

 knee. 0*15 oz. 



2. M. rectus femoris («). Origin: from anterior spine of 

 ilium, close to the acetabulum. Insertion : as in leg of Ostrich, 

 into a tendon passing over the knee, outwards, and terminating 

 in a remarkable muscle* [x) in the calf of the leg, associated 

 with the gastrocnemius (m), and deriving a second origin from 

 the agitator caudse (c), as shown in the figure. 008 oz. 



3. M. agitator caudse (c). Origin; from the ischiadic line, 

 behind the glutseus maximus. Insertion : by a double tendon. 

 (1) One tendon passes through a pulley on the outside of the 

 knee, formed by the tendon of the biceps [d) as it passes to its 

 fibular insertion, and is inserted in the head of the muscle {x) 

 in the calf of the leg. (2) The second insertion is by means 

 of a tendon that goes to the top and front of the tibia ; this 

 second tendon also serves to strap down the tendon of the rectus 

 femoris [a). 0"03 oz. 



4. M. biceps femoris [d). Origin : from the ilio-ischiura, 

 under and behind the origin of the glutseus maximus. Inser- 

 tion : partly into the top of the fibula, forming a ])ulley for the 

 agitator cauda; (c), and an additional strap for the rectus fe- 

 moris (a), and partly, by means of another tendon, into the 

 head of the peronseus longus (y). 0*05 oz. 



5. M. semitendinosus (e). Origin: from the posterior point 

 of the tuber ischii. Insertion : by a remarkable looped tendon 

 having one end inserted into the back of lower end of femur, 

 and the other end into the os calcis. 0*18 oz. 



6. M. semimembranosus (/). Origin: tuber ischii. Inser- 

 tion : into the top of the tibia, by a tendon common to this 

 muscle and the gracilis. 0"11 oz. 



The muscles of the calf, shown in the figure, are the follow- 

 ing :— 



7. M. gastrocnemius [u). This muscle, as usual, has an outer 

 and inner head. 0-14 oz. Outer head: — Origin : from the tendon 

 of the great caudal extensor of the thigh, half an inch from its 

 insertion into the outer condyle. Insertion : into the under side 

 of the outer tarsal bone (vide a, fig. B) and into the plantar 

 fascia. O'll oz. Inner head: — Origin: from the top of fibula 

 and inner condyle of femur. Insertion : by a tendon, which 

 unites with that of the outer head before reaching the os calcis, 



* This muscle may be the plantaris. 



