224 THE ARTISTIC ANATOMY OF ANIMALS 



the external divides to pass towards each of the two small 

 toes, and towards the great ones ; but this latter disposition 

 is not constant. 



By its contraction the muscle which we have just studied 

 extends the phalanges and flexes the foot. 



Peroneus Tertius. — This muscle is not found in domestic 

 quadrupeds. 



We should remember, nevertheless, that certain authors 

 consider as representing it the tendinous portion of the 

 anterior tibial of the horse, or the corresponding portion 

 now fleshy, of the same muscle in the pig and the ox. It 

 is by reason of this fact that it is called the third peroneal, 

 notwithstanding that in the numerical order of the peroneals 

 it is rather the first. 



But that which still further complicates this question of 

 nomenclature is that some authors give this name of third 

 to a peroneal which, in the carnivora, is situated more de- 

 finitely in the group of external muscles (see below. Short 

 Lateral Peroneal). 



Muscles of the External Region 



In man, two muscles constitute this region ; they are 

 the peroneus longus and peroneus brevis. 



Peroneus Longus (Fig. 84, 9 ; Fig. 85, 7). — This muscle 

 does not exist in the domestic animals ; only in the flesh- 

 eaters, the pig and the ox excepted. 



It is in relation superiorly with the tibialis anticus, and 

 interiorly with the common extensor of the toes ; in the 

 ox, it is in contact with this latter muscle throughout its 

 whole length. 



The peroneus longus arises from the external tuberosity 

 of the tibia ; towards the middle of the leg it is replaced by 

 a tendon. This proceeds towards the tarsus, but previously 

 it passes between the tibia and fibula. In the ox it is 

 situated in front of the coronoid tarsal bone ; we recol- 

 lect that this bone is regarded as representing the in- 

 ferior extremity of the fibula (see p. 97). Then it passes 

 into a groove belonging to the cuboid bone or to the cuboido- 

 scaphoid bone in the ox, traverses obliquely the posterior 



