232 ELEMENTARY BIOLOGY. [CHAP. 



P. The tibialis posticus : a slender muscle co- 

 vered in great part by the gastrocnemius ; it 

 arises from the greater part of the posterior 

 surface of the os cruris and, passing along the 

 inner side of the ankle-joint, is inserted into 

 the astragalus. 



b. On the opposite side of the bone lie four mus- 

 cles : viz. 



a. The peroneus: the largest and most external; 

 it arises from the outer side of the distal arti- 

 cular end of the femur and, running past the 

 outer side of the ankle-joint, is inserted into 

 the calcaneum. 



P. The tibialis anticus : a small muscle inside 

 and beneath the peroneus ; it arises from the 

 front of the lower end of the femur and from 

 the capsule of the knee-joint; below it di- 

 vides into two parts, one inserted into the 

 dorsal side of the astragalus, the other into 

 the calcaneum. 



y. The extensor cruris brevis : this lies internal to 

 the upper part of the last muscle; it arises 

 from the front of the distal articular end of 

 the femur and is inserted into the middle third 

 of the os cruris. 



8. The flexor tarsi anterior : this arises where 

 the last muscle ends, and is inserted into the 

 dorsal side of the astragalus. 



6. The nerves of the hind-limb. 



These are now to be dissected out in that leg which 

 has not been used for the muscles. 



