MYOLOGY 215 



In the dog and the cat this muscb, which is rather large, 

 arises from the external tuberosity of the tibia and from the 

 crest of this bone. In its superior part it is flat, but lower 

 down it is thick and produces a prominence in front of the 

 tibia. Finally, it becomes tendinous, and passes towards 

 the tarsus ; thence it is directed towards the inner side of 

 the metatarsus, and is inserted into the great-toe, this latter 

 being sometimes well developed, but also often merely repre- 

 sented by a small bony nodule on which the muscle is then 

 fixed. 



In the other animals with which we here occupy ourselves, 

 the tibialis anticus presents a complexity which would be 

 incomprehensible unless this muscle be first studied in 

 the horse. 



In this latter the tibialis anticus consists of two distinct 

 portions, placed one in front of the other : a fleshy portion, 

 and a tendinous portion running parallel to it. 



The muscle is covered, except on its internal part and 

 inferiorly, by a muscle with which we will occupy ourselves 

 later on — that is, the common extensor of the toes. 



The tendinous portion of the tibialis anticus (Fig. 83), 

 especially covered by the extensor of the toes, arises from 

 the inferior extremity of the femur, from the fossa situated 

 between the trochlea and the external condyle ; thence it 

 descends towards a groove which is hollowed out on the 

 external tuberosity of the tibia, and is directed towards the 

 tarsus, where it divides into two branches, which are 

 inserted into the cuboid bone and the superior extremity of 

 the principal metatarsal. These two parts form a ring 

 through which the terminal tendon of the fleshy portion of 

 the same muscle passes. 



This fleshy portion, situated behind the preceding, arises 

 from the superior extremity of the tibia, on the borders of 

 the groove in which the tendinous portion lies ; thence it 

 passes downwards for a short distance on the inner side of 

 the common extensor of the toes, which covers it in the rest 

 of its extent. It ends in a tendon which, after passing 

 through the tendinous ring above noticed, divides into 

 two branches. One of these branches is inserted into 



