The two fasciculi then pass towards the knee, being in relation with the rectus and the vastus internus of the triceps. The anterior fasciculus is inserted into the patella. The posterior unites with the tendons of the gracilis (see below) and semi-tendinosus, and then proceeds to be inserted into the superior part of the internal surface of the tibia. On account of their different insertions these two parts receive the names of _the patellar sartorius_ and _tibial sartorius_ respectively. In the ox and the horse the sartorius is still more definitely situated on the internal surface of the thigh. Consisting of a single fasciculus, representing the tibial sartorius of the cat and the dog, it arises in the abdominal cavity from the fascia covering the iliac muscle, then passes under the crural arch, and terminates, by an aponeurosis which blends with that of the gracilis, on the inner fibres of the patellar ligament. In short, the sartorius is of interest to us in the carnivora only, and especially on account of its anterior or patellar fasciculus. It is an adductor of the leg and a flexor of the thigh. Muscles of the Internal Region The ilio-psoas pectineus and the adductors which we study in man, in connection with the internal aspect of the thigh, offer little of interest from the point of view of external form in quadrupeds; it is for this reason that we will disregard them. The gracilis alone merits description. =Gracilis= (Fig. 87, 9; Fig. 88, 6).--Designated in veterinary anatomy under the name of _the short adductor of the leg_, this muscle, expanded in width, occupies the greater part of the internal surface of the thigh, _or flat of the thigh_, as this region is also called. Let us imagine, in man, the internal surface of the thigh broader, and the internal rectus more expanded, and we shall have an idea of the same muscle as it exists in quadrupeds. The gracilis arises from the ischio-pubic symphysis and from the neighbouring regions; thence it is directed towards the leg to be inserted into the superior part of the internal surface of the tibia, after being united to the tendons of the sartorius and semi-tendinosus. We find, accordingly, at this level, an arrangement which recalls the general appearance of what in man receives the name of _the goose's foot_ (_pes anserinus_). It is between this muscle and the sartorius, at the superior part of the internal surface of the thigh, in the region which recalls the triangle of Scarpa, that we are able, especially in the cat and the dog, to see the adductor muscles of the thigh. We also partly see there, in these animals, the vastus internus and the rectus of the triceps (see Fig. 87). The gracilis is an adductor of the thigh. Muscles of the Leg