THE MUSCLES. 155 



tor ani, with which it forms the floor of the pelvis. Or. : ten- 

 dinous from Spina Ischii and lig. spinos o-sacrum. Ins. : Os 

 coccygis (border and anterior surface), Os sacrum (apex). Use: 

 assists in bending the coccyx forwards ; both acting together fix 

 it (in ejection of the semen). 



273. 4. Curvator coccygis. 



Pos. : upon the anterior surface of the coccyx, mostly tendi- 

 nous. Or. : from the sides of the apex of the os sacrum. Ins.: 

 apex of coccyx. Use : to bend the coccyx. 



274. 5. Extensor coccygis. 



Pos. : upon the posterior surface of the coccyx, mostly tendi- 

 nous. Or. : from the apex of os sacrum spin, ilei poster, infer. 

 Use : to draw the coccyx backwards. 



275. 6. Levator Ani. 



Pos. : before the preceding muscle, anteriorly narrow, behind 

 broad; four-sided; covered by fascia pelvis ; below, by sphincter 

 ani, and behind by M. glutseus max. ; before, by M. obturator 

 intern. Between the anterior borders of the two decussating 

 muscles and the pubic arch a longitudinal fissure remains, through 

 which the urinary and genital organs pass out. Or. : 1 . ramus 

 descend, pubis (internal surface), as far as, 2. Spina Ischii. 

 Ins.: 1. the sides of the Prostata, urinary bladder, and the 

 Rectum. 2. the apex of the coccyx as far as sphincter ani. M. 

 pubo-urethralis, a thin fasciculus which passes to the urethra. 

 Use : draws the anus backwards and upwards, expands it (in the 

 act of defecation), likewise the coccyx, contracting the pelvic 

 outlet. [Or. : from a fibrous cord extending from the body of 

 the Pubis to the spine of the Ischium.~] 



276. 7. Ischio-cavernosus, s. erector penis, s. clitoridis. 

 Pos.: close to the ram. ascendens oss. ischii; covered below 



by fibro-cellular tissue, above by corp. cavernosum; internally 

 lies M. bulbo-cavernosus, separated from it by a triangular space. 

 Or. : tuber ischii and ram. ascendens. Ins. : Corp. cavernosum 

 penis; to the entire length of the Crus. Use: presses the root 

 of the Penis against the bones, maintaining the already erect organ 

 in a direction forwards ; does not compress, but widens* the root 

 of Corp. cavernosum penis. 



277. 8. Bulbo-cavernosus s. accelerator urinse [s. ejaculator 



seminis~]. 

 Pos. : before the anus, below and along the bulbus and the 



