72 ANATOMY OF THE WOOD EAT 



M. gluteus superficialis (figs. 6, 7, 32, 33). This is a 

 muscle consisting of what are usually termed tensor fasciae 

 latae or femoris, and sartorius. Because it is usually 

 treated incorrectly it had better be called the gluteus super- 

 ficialis. It has two origins and two insertions, and hence, 

 although indivisible, it should be described in two parts. 



Pars anterior arises from the cranial part of the ven- 

 tral border of the ilium. Its latero-caudal portion is con- 

 tinuous with and inseparable from the posterior part, and 

 insertion is weakly onto the fascia just proximad of the 

 knee. In those lower mammals in which this muscle is 

 present it seems invariably to have been called sartorius. 

 In position and action it is somewhat analogous to that 

 muscle, but were it homologous, the innervation would be 

 by the femoral nerve. Such is not the case, however, for 

 it is served by a branch of the N. gluteus superior, a fact 

 established by the dissection of three specimens. It should 

 be considered as a specialization of the posterior part of 

 this muscle. In Teonoma this is somewhat heavier and 

 extends farther caudad upon the medial side of the leg. 



Pars posterior takes origin broadly from the dorsal 

 fascia, and passing latero-ventrad, the fibers converge to an 

 insertion by aponeurosis upon the lateral crest of the femur. 

 This part is undoubtedly homologous with the tensor 

 fasciae latae, but it is also a part of the gluteal mass, in 

 action, location and innervation. 



As already mentioned the innervation of this muscle is 

 by the superior gluteal nerve. 



M. gluteus maximus (figs. 6, 32). I do not agree with 

 Parsons (1894, p. 282; 1896, p. 178) in considering that this 

 muscle forms part of the tensor latae (or gluteus super- 

 ficiaUs) sheet. I do not know what he had in mind, but the 

 gluteus maximus is perfectly distinct in most rodents which 

 I have dissected, occupying its normal position. When not 

 distinct it should be considered as having fused with 



