THE HIP-BONE. 113 



extending on to the posterior inferior spine behind ; 3, some depressions for the attach- 

 ment of the posterior sacro-iliac ligament ; and 4, a rough surface reaching up to 

 the hinder portion of the iliac crest, and giving origin to parts of the erector and 

 multifidus spinse muscles. 



The iliac crest gives attachment by its outer lip to the tensor vaginas femoris, obliquus 

 externus, and latissimus dorsi muscles, and the gluteal fascia ; by its middle ridge to the 

 internal oblique ; and by its inner lip to the transversalis, quadratus lumborum, and erector 

 spinae muscles, and the iliac fascia. To the anterior superior spine are attached the tensor 

 vaginae femoris externally, the sartorius in front, and Poupart's ligament internally. The 

 anterior inferior spine gives origin to the straight head of the rectus femoris muscle. Between 

 this and the margin of the acetabulum is an impression where the ilio-femoral ligament 

 is fixed to the bone. The iliac part of the ilio-pectineal line gives attachment to the iliac and 

 obturator fasciaa, and the tendon of the psoas parvus when that muscle is present. 



The os pubis forms the anterior wall of the pelvis, and bounds the thyroid 

 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 presents an elongated oval surface 

 which forms the articulation with the bone of the opposite side, the junction being 

 called the symphysis pubis. The part which passes downwards and outwards below 

 the symphysis is called the inferior or descending ramus, the upper part is called the 

 superior or ascending ramus, and the flat portion between the rami is the body. The 

 deep or pelvic surface of the body is smooth ; the anterior or femoral surface is 

 roughened near the symphysis by the attachments of muscles. At the superior 

 extremity of the symphysis is the angle of the pubis, and extending outwards from 

 this on the superior border is the rough pubic crest, terminating in the projecting spine. 

 The inferior ramus is thin and flattened, and joins the ramus of the ischium. The 

 superior ramus becomes prismatic, and increases in thickness as it passes upwards 

 and outwards. Its superior border is the pubic portion of the ilio-pectineal line, a 

 sharp ridge continued from the iliac portion of the line downwards and inwards 

 to the pubic spine. The triangular surface in front of this line is covered by 

 the pectineus muscle ; it is bounded externally by the ilio-pectineal eminence, 

 and below by the prominent obturator crest, which extends from the pubic 

 spine to the acetabular margin at the anterior extremity of the cotyloid notch. 

 Behind the outer part of the crest, on the inferior surface of the ramus, is the 

 deep obturator groove, directed from behind forwards and inwards, for the obturator 

 vessels and nerve. 



The pubic crest gives origin to the rectus abdominis and pyramidalis muscles. The pubic 

 spine serves for the insertion of Poupart's ligament ; and for a short distance outside this 

 Gimbernat's ligament and the conjoined tendon of the internal oblique and transversalis 

 muscles are fixed to the ilio-pectineal line. Along the front of the pubic portion of the ilio- 

 pectineal line the pectineus muscle arises, and to the line itself the pubic portion of the fascia 

 lata is attached. From the front of the pubis the adductor longus muscle arises in the angle 

 between the crest and symphysis, and below this the adductor brevis and upper part of the 

 adductor magnus. Internally to these the gracilis is attached to the prominent edge of 

 the surface, and externally the obturator externus. Along the margin of the symphysial 

 surface is a small rough area, which is occupied by the anterior ligament of the articulation, 

 and is wider in the female than in the male bone (Cleland). The posterior surface of the pubi^ 

 gives attachment to part of the obturator internus muscle ; and above this, where a faint line 

 may sometimes be recognized passing obliquely from the upper margin of the obturator foramen 

 to the lower end of the symphysis, the levator ani and obturator and recto-vesical fasciae are 

 fixed together to the bone. 



The ischium forms the posterior and inferior part of the hip-bone, and bounds 

 the thyroid foramen in the lower half of its extent. Superiorly it enters into the 

 acetabulum : inferiorly it forms a thick projection, the tuberosity, and this part, 

 diminishing in size, is continued forwards into the ramus. On its posterior border, 



