114 ANATOMY OF THE DOMESTIC FOWL 



the semitendinosus. The inferior tendinous portion passes through 

 a tendinous sHng or pulley called the biceps band. • 



Action. — Flexes the leg upon the thigh. 



Semitendinosus (Fig. 23, No. 10). Location. — Posterior femoral 

 region. 



Origin. — By a tough, strong fascia from the surface of the caudal 

 muscles and from the posterior third of the post-acetabular ridge. 



Insertion. — The fibers pass downward and forward, and insert to 

 the tendinous raphe along the posterior margin of the semitendinosus 

 accessorius; lower down it merges with the median fascia of the 

 inner head of the gastrocnemius. 



Shape. — Fleshy, broad, flat and long. 



Relations. — Internally, with the semimembranosus and anteriorly, 

 with the biceps flexor cruris. 



Action. — Flexes the leg. 



Semitendinosus Accessorius. Location. — Posterior femoral region. 



Origin.— Yxoxa an obhque line just above the condyle, on the 

 posterior of the shaft of the femur. 



Insertion. — Its fibers, passing upward and backward, attach them- 

 selves to the tendinous raphe common to this muscle and the semi- 

 tendinosus, and are finally inserted to the inner side of the shaft of 

 the tibia. 



Shape. — Flat, oblong. 



Relations. — Posteriorly to the shaft of the femur, and externally 

 to the long adductors of the thigh. 



Action. — ^Aids the preceding in flexing the leg. 



Semimembranosus (Fig. 24, No. 17). Location. — Postero-internal 

 to the semitendinosus. 



Origin. — From the outer surface of the ischium, beginning at the 

 lower margin of its notch on the posterior pelvic border, extends on 

 a curved Une on the adjacent surface beyond. 



Insertion. — The fibers, passing downward and forward, insert by a 

 broad, thin tendon to the shaft of the tibia a short distance below 

 the head and on a line parallel to the long axis of the tibia. 



Shape. — Long, narrow, ribbon-shaped. 



Relations. — Lies adjacent to the semitendinosus and in the same 

 plane. 



Action. — Directly flexes the leg. 



Femoro-caudal (Fig. 24, No. 8). Location. — Infero-lateral to 

 the caudal and post-femoral region. 



