MYOLOGY 231 



that of this same muscle in the human species. From this 

 independence there results a special action. 



It is an adductor and internal rotator of the foot. 



Flexor Longus Pollicis (Fig. 84, 18 ; Fig. 85, 14 ; 

 Fig. 86, 12 ; Fig. ^y, 18 ; Fig. 88, 16). — This muscle, as 

 that in man, is the most external of the deep layer of the 

 leg. It is on the external aspect of the latter we perceive 

 it, between the peroneals and the gastrocnemius or tendo- 

 Achillis. 



It arises from the fibula and tibia, and is thence directed 

 towards the tarsus. It unites with the long common flexor 

 of the toes to form with it the deep flexor of the -phalanges, 

 of which it is the principal fasciculus. We may add that in 

 the dog and the cat the posterior tibial remains independent 

 of this latter, but that in the pig, ox, and horse the posterior 

 tibial is united to the preceding to form with them the deep 

 flexor muscle. 



Thus constituted, the deep flexor goes towards the 

 phalanges, where it terminates as the deep flexor of the 

 digits of the fore-limbs (see p. 197). In animals possessed 

 of a canon it contributes to form the tendon (Fig. 85, 16 ; 

 Fig. 86, 14, 14 ; Fig. 88, 19, 19). 



Muscles of the Foot 



We must remember that on the dorsal surface of the foot 

 in man we find but a single muscle — the dorsalis pedis. 

 The remaining subcutaneous structures of this region 

 consist of the tendons of the anterior muscles of the leg 

 which occupy this dorsal aspect. 



Dorsalis Pedis (Fig. 84, 19).— Also called the extensor 

 brevis digitorum, the dorsahs pedis muscle is found in all 

 domestic quadrupeds ; but its development is so much the 

 less as the number of digits is more reduced. 



In the dog and the cat it arises from the calcaneum, and 

 is inserted into the three internal toes (the first toe excepted) 

 by uniting with the corresponding tendons of the common 

 extensor. 



In the pig its disposition is analogous. 



