of the Ley 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 maximus (b). Origin: from central half of 

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

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

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

 knee. 015 oz. 



2. M. rectus femoris (a). 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 (u), and deriving a second origin from 

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



3. M. agitator caudae (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 (rf) 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-ischium, 

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

 tion : partly into the top of the fibula, forming a pulley for the 

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

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

 head of the peronaeus longus (y). - 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. - ll 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. 0*11 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. 



