198 THE MUSCLES. 



Insertion on a long S-shaped line which begins on the 

 dorsal border of the tibial shaft about two centimeters from its 

 proximal end, passes thence to the middle of the proximal end 

 of the medial surface of the tibia, thence across the ligaments 

 of the knee-joint and the medial surface of the medial epicondyle 

 to the patella, crosses the patella obliquely to the middle of its 

 proximal end, and may be continued for some distance proximad 

 along the middle line on the fascia. 



Relations. — Medial surface with the integument and proxi- 

 mad with the internal oblique muscle (Fig. 68, f). Lateral 

 (inner) surface with the tensor fascia latas (Fig. 68, r), the 

 vastus lateralis (Fig. 90, <f), the superficial fascia, the vastus 

 medialis (Fig. 92, r), the rectus femoris (Fig. 92, b), and the 

 distal end of the semimembranosus (Fig. 92, //'). 



Actioji. — Adducts and rotates the femur and extends the 

 tibia. 



M. gracilis (Fig. 91, b). — The gracilis is a flat, thin, sub- 

 cutaneous muscle occupying the ventral half of the medial sur- 

 face of the thigh. 



Origin by a strong tendon from the caudal three-fourths of 

 the symphysis of the ischium and pubis. The tendon may 

 extend caudad of the symphysis in the middle line to the level 

 of the tuberosity of the ischium. For about its first centimeter 

 the tendon is common to the two muscles of opposite sides and 

 gives origin on two sides to the fibres of the adductor femoris. 

 The common tendon divides into two which pass laterad, each 

 ending in a convex border from which the muscle-fibres 

 spring. 



Insertion. — It ends in a thin aponeurosis, part of which is 

 continuous with that of the sartorius. The aponeurosis is finally 

 inserted into the medial surface of the tibia near its proximal 

 end, while distally it is continuous with the fascia. 



Relations. — Outer (medial) surface with the integument. 

 Inner (lateral) surface with the semimembranosus (Fig. 91, /) 

 and the adductor femoris (Fig. 91, //). 



Action. — Adducts the leg and draws it caudad, 



M. adductor femoris (magnus et brevis) (Fig. 92, ^; Fig. 

 90, //). — The adductor femoris lies between the semimembrano- 



