126 The Alligator and Its Allies 



Achilles, which portion may be followed to the 

 rudiment of the fifth toe. On the outer side of 

 this toe rudiment is attached a tendon from the 

 tibial border of the muscle. 



In the crocodile. This muscle is here divided 

 into two parts, of which the one that springs from 

 the anterior surface of the fibula is inserted on the 

 toe rudiment, while the greater and outward part 

 extends over the calcaneum bone and has the same 

 distribution as in the alligator. 



Peroncus Posterior (Plate IV., Figs. 3 and 4, peron. 

 post., Plate V., Figs. 2 and 3, peron. post.) (Plan- 

 tans). Springs chiefly from the tendon of the 

 ambiens muscle running over the knee and forms 

 the direct continuation of this muscle. Besides 

 this come tendinous fibers from the insertion 

 tendons of the femoro-tibialis and extensor ilio- 

 tibialis muscles; and finally supporting fibers from 

 the outer, end-tendon of the ilio-fibularis muscle. 

 The fibers of this muscle pass partly into the 

 fibular portion of the caput femoralis of the gas- 

 trocnemius, while the chief mass of the muscle is 

 inserted on the posterior surface of the calcaneum. 



Gastrocnemius (Plate III., Figs, i and 3, cap. 

 int. gastr., Plate IV., Fig. 4, cap. int. gastr. and 

 cap. ext. gastr., Plate V., Figs. 2 and 3, cap. ext. 

 gastr. and cap. int. gastr.) (Solenmuskel, Outer 

 head of gastrocnemius) . This is the strongest 

 superficial flexor muscle on the posterior surface 

 of the lower leg; it consists of two heads: I. 



