MYOLOGY 81 



of the insertional end of the latter muscle and the semi- 

 membranosus anticus. 



In Teonoma the insertion of the last-mentioned muscle 

 is located slightly more cranio-dorsad, so that the part of 

 the adductor passing to the femoral epicondyle is com- 

 pletely separated from the remainder of the muscle, and the 

 femoral artery thus passes between the two slips. This is 

 also the case in Neotoma, but to a slightly lesser degree. 

 Attention may be called to the fact that the adductor 

 magnus is a double muscle, and its form and function 

 among the lower MammaHa offers an interesting and im- 

 portant subject for study. 



The innervation of the graciUs, adductores longus, 

 brevis, and the more lateral part of the magnus, is by the 

 obturator nerve, while the more medial portion of the 

 last muscle is served by the N. ischiaticus. 



C. MUSCLES OF THE LEG 



The present scheme of muscle arrangement for the lower 

 leg into groups containing flexors, extensors, and peroneal 

 muscles, and based also on the innervation, seemingly 

 shows a number of anomalies, for the flexor group as here 

 presented contains muscles that both extend and flex the 

 ankle. These muscles, nevertheless, comprise a flexor 

 group and are similarly innervated, and this arrangement 

 will be employed for the present. 



The flexor group, then, of the lower leg contains the 

 following eight muscles: 



Mm. gastrocnemius medialis popliteus 



gastrocnemius lateralis flexor digitorum longus 



plantaris flexor digitorum fibularis 



soleus tibialis posticus 



The first four of these muscles compose the M. quadriceps 

 surae, whose tendons extend to form the tendo calcaneus. 



