THE MUSCLES. 17] 



lumbar vertebrae. Ins. : Fascia iliaca at the posterior part of 

 linea arcuata. Use: stretches the fasc. Iliaca; may flex the 

 pelvis towards the trunk (as in climbing), or draw the trunk side- 

 ways. 



340. 3. Glut sens maximus. 



Pos. : one inch thick, close beneath the skin of the buttocks ; 

 broad, four-sided; covers glut. med.,pyriform., gemelli, obturat. 

 intern., quadrat, femor., incisura ischiad. maj., tuber iscliii, 

 Mm. semitendin. and membranos., cap. long, bicipit.; tro- 

 chanter major, adductor magn., Nn. et vasa glutsea, ischiadic., 

 pudenda interna. Or.: 1. posterior surface of Ilium, behind lin. 

 semicircul. poster. 2. spina ilei poster, super, as far as cornu 

 sacrale. Ins. : Linea aspera, the external crus, close under tro- 

 chanter major femoris, and fascia lata. Use : extends the thigh 

 backwards, draws and rotates it outwards ; or draws (when stand- 

 ing upon one leg), the pelvic half of the other side, backwards ; 

 stretches the fascia lata, and maintains the os. coccygis in its 

 situation. 



Nerves : glutceus infer. 



341. 4. Glutseus medius. 



Pos. : behind the last, covered before and above by fat and skin, 

 and rather by m. fascise latse. Along the posterior border, m. 

 pyriform. ; on the outside, Vasa and nerv. Glutsei. 



Or. : fossa Iliaca externa ; the anterior portion from Spina 

 oss. Ilei anter sup. and (three fourths) Crista ilei: the posterior 

 from linea semicircula superior. Ins. : trochanter major (from 

 the apex to the base). Use : extends and abducts the thigh ; the 

 anterior portion rotates it inwards (and helps to flex it). 



Nerves : glutaus superior. 



342. 5. GlutsBus minimus. 



Pos. : Three-sided ; covered behind, slightly, by pyriformis, 

 above by vasa glutsea, entirely by glutseus med., meets anteriorly 

 with tensor fascise, covers the upper part of the capsule of the 

 hip joint. Or. : fossa iliaca externa below linea semicircul. in- 

 fer.; Crista Iliaca (anterior portion), incisura is chiadica (external 

 portion). Ins. : trochanter major (anterior surface). Use : draws 

 the thigh directly outwards ; the anterior portion rotates it in- 

 wards, the posterior outwards. 



343. 6. Pyriformis. 



Pos. : covered by glut, med., in the incisura ischiadica major, 

 almost horizontal along the lower border of glut. med. ; in the 



