-^(,2 BONES OF THE LOWER LIMB. 



anterior extremity, arches backwards to the upper part of the great 

 sciatic notch, while the other, the wfmor currcil Ihu, shorter and less 

 strono'ly marked, extends from the space between the anterior spinous 

 processed to the middle of the great sciatic notch. The curved space 

 between the crest and the superior curved line, broad behind and 

 pointed in front, gives attachment to the gluteus medius muscle, while 

 that between the two curved lines gives attachment to the gluteus 

 minimus. The internal surface of the ilium is divided into three 

 parts. The anterior of these, the largest, is called the iJiar fomi ; it 

 is concave and smooth, and towards the middle of it the bone is very 

 thin. The posterior part is subdivided, presenting inferiorly, for 

 cartilaginous articulation with the sacrum, the smooth but uneven 

 (mricular mrface, broad in front and extending to the posterior inferior 

 spine behind ; and superiorly a more uneven and rough surface for 

 the attachment of ligaments. The third part, entering into the forma- 

 tion of the true pelvis, is not distinguished by any mark in the adult 

 from the ischium and os pubis ; it is separated from the iliac fossa 

 by a smooth border, the iliac portion of the ilio-ppcfincal line, which 

 extends from the auricular sm-face to the pubic spine. 



Fig. 89. — RrcHT Os Innojiixatum, 



FROM THE INNEU OR PELVIC 

 SURFACE. (A. T.) J 



1, 2, 3, 4, 5, 16, 17, and IS, 

 indicate tlie .same parts as in the 

 preceding figure ; l!l, iliac fossa ; 

 20, ilio-peetineal line ; 21, aiiricu- 

 lar cartilaginous .sacro-iliac .surface; 



22, rough tuberculated surface for 

 tlie posterior sacro-iliac ligaments ; 



23, oval surface of the symphysis 

 pubis ; 24, spinous jirocess ; 25, 

 angle of the os pubis ; between 24 

 and 25, the crest ; between 17 and 

 20, the pelvic surface of the ilium. 



The OS pubis forms the 

 anterior wall of the pelvis, 

 and bounds the obturator 

 foramen in the upper half 

 of its extent. At its outer 

 and upper extremity it forms 

 a part of the acetabulum ; 

 at its inner extremity it pre- 

 sents an elongated oval sur- 

 face, articulating by fibro 

 cartilage with the bone of the opposite side, its junction with which 

 is called the sijmj)Ii//sis j)uhis. The part wliich jjasses downwards and 

 outwards below the symphysis is called the inferior or descetidinrf 

 ramus, the upper part is called the superior or asreiulin/j ramus, and 

 the flat portion between the rami may be distinguished as the bodii. 

 Tlie deep or pelvic surface of the os pubis is smootli ; the outer sur- 

 face is roughened near the symphysis by tlie attachments of muscles. 

 At the superior extremity of the symphysis is the aunle of the pubis, 

 and extending outwards from tliis, ou the superior border, is the 



