104 THE SALAMANDER 



This muscle arises from the ventral surface of the pelvic girdle, its 

 posterior portion lying deep to the M. pub. isch. tib. It tapers 

 sharply, so that it has a triangular shape when seen from the ventral 

 side. It is inserted along the middle of the ventral surface of the 

 femur. Appleton regards the muscle as being composed of two 

 sections, and calls them respectively obturator anterior and posterior. 

 There is considerable justification for this view, but, since in the 

 adult they have fused indistinguishably into a single mass, the older 

 name is adhered to. There is, however, an anterior slip of muscle 

 arising from the pubis which is distinct, but which was probably 

 included by the older authors as forming part of the muscle just 

 described (see p. 1 06). 



Innervation : This muscle has a double innervation in accord with 

 its double nature. The anterior fibres (Appleton 's obturator anterior) 

 are supplied by the obturator nerve, while the posterior fibres 

 (Appleton's obturator posterior) receive their supply from the N. 

 ischiadicus ventralis. 



Function : It is the true flexor of the hip-joint. 



M. ischio-femoralis (m.is.fm.). Mivart (1869); de Man (1873); 

 Osawa (1902). 



Gemellus Meckel (1828). 



„ s. quadratus femoris . . . Stannius (1854). 



Anterior abductor Rymer Jones (1852}. 



Hinder (ischio-femoral) part of deeper stratum of thigh 



Humphry (1872) 

 Ischio-femoralis (quadratus femoris ) . . Hoffmann (1873-8). 



Rotateur inverse du femur (124) .... Perrin (1892). 



Ischio-femoralis a and jS Low (1926). 



Together with previous muscle = 



Flexor profundus Appleton (1928). 



This is a small, short muscle which arises from the posterior sector of 

 the concave lateral border of the ischium, and passes in a latero-dorsal 

 direction to its insertion on the posterior face of the head of the femur. 



Innervation-. From N. ischiadicus ventralis. 



Function: It tends both to depress and to retract the femur, or, 

 conversely, to support and project the pelvis. 



With reference to the phylogeny of the ventral thigh muscles 

 described above, the conclusions of Appleton (1928, p. 427) may 

 be quoted. 



'It is concluded that some modification has occurred in the superficial ventral 

 thigh muscles of Urodela to which the extensive distribution of N. ischiadicus 



