500 



Fig. 34. 



s. m, 



ac. 



Semimembranosus. 

 Accessorius. 

 Common tendon. 



a. , . . Portion of tendon ending in gas- 



trocnemius. 



b. , . . Portion of tendon ending in tibia. 



18. M. semitendinosus, 



0-71 oz. 



Arises from the lower margin of the anterior half of the ischium (Pig. 32, 

 s. t.), and is inserted by means of a* broad tendon into the fascia of the 

 upper and inner part of the leg, with a slip passing on to the heel. 



Arises from the anterior spine of the pubes (Pig. 32, gr.), and termi- 

 nates in a slender tendon which passes oyer the patella, from within 

 outwards, across the knee joint under the anterior head of the gastro- 

 cnemius and solccus, outwards and downwards to the calf of the leg, 

 being strapped down by the tendon of the biceps at its insertion into 

 the fibula, at one inch below which it expands into a fan-shaped tendon 

 spread over the back of the fascia, enclosing the first flexor perforatus 

 digiti medii and the flexor perforatus digiti externi; this fan- shaped ex- 

 pansion of the tendon of gracilis is also connected by means of an auxiliary 

 tendon passing backwards, with the inner side of the head of the second 

 flexor perforatus digiti medii. The three tendons of the flexors just 

 named, and so placed in relation with the gracilis, pass together into the 

 toes. 



"N. B. — The gracilis muscle in the Ehea performs the mechanical 

 duty assigned by me to the rectus femoris in the Ostrich, and serves to 

 bring into simultaneous action all the flexors of the foot and extensors 

 of the leg. 



20. M. sartorius, 2*80 oz. 



Arises from the anterior surface of the ilium (Pig. 32, 5. *.), and from 

 the backs of the last two ribs overlying the gluteus medius ; and is 

 inserted by a broad tendon into the head of the tibia. 



21. M. rectus femoris, none. 



22. M. vastus externus (1), (Pig. 33, v. e. 1), . . . . 5*07 oz. 

 Origin and insertion as in Emu. 



23. M. vastus externus (2), (Pig. 33, x. e.2), .... 0-40 oz. 



19. M. gracilis, 



0-12 oz. 



