210 THE ARTISTIC ANATOMY OF ANIMALS 



Muscles of the Anterior Region. 



First we recall that in man the anterior muscles of the 

 thigh are : the triceps cruris, the tensor of the fascia lata, 

 and the sartorius. 



Triceps Cruris (Fig. 8, 36 ; Fig. 69, 31 ; Fig. 70, 41 ; 

 Fig. 84, 2 ; Fig. 87, 3 ; Fig. 88, 3). — This muscle, which 

 occupies the greater part of the space between the pelvis 

 and the anterior aspect of the femur, consists of three parts : 

 an external, or vastus externus ; an internal, or vastus in- 

 temus ; and a median or long portion, or rectus femoris. 

 This division accordingly recalls that which characterizes 

 the human triceps cruris. Furthermore, as in the case 

 of the latter, the vastus externus and the vastus internus 

 take their origin from the shaft of the femur, while 

 the long portion arises from the pelvis. The vastus 

 externus arises from the external lip of the linea aspera 

 of the femur (or from the external border of the pos- 

 terior surface of this bone in the ox and the horse, in 

 which the linea aspera, considerably widened, especially 

 in the latter, forms a surface), and from the external sur- 

 face of the shaft of the femur. From this origin its fibres 

 pass downwards and forwards, to be inserted into the tendon 

 of the long portion of the muscle and into the patella. 



In the dog and the cat the vastus externus is the most 

 voluminous of the three portions which constitute the 

 triceps muscle. It is covered by the fascia lata ; but not- 

 withstanding this, its presence is revealed by a prominence 

 which occupies the external surface of the thigh, and 

 surmounts, in the region of the knee, the more slightly 

 developed one which is produced by the knee-cap. 



The vastus internus, situated on the inner surface of the 

 thigh, takes its origin from the corresponding surface of 

 the femur, and proceeds towards the patella. 



The rectus femoris arises from the iliac bone, above the 

 cotyloid cavity ; its fleshy body, which is fusiform, and 

 situated in front of and between the two vasti muscles, is 

 directed towards the patella, into which it is inserted by 

 a tendon, which receives the other two portions. 



