222 A MANUAL OF ANATOMY 



there is a groove for the passage of the iHo-psoas, and internal to 

 the groove is the ilio -pectineal eminence, which marks the junction 

 of the ilium and superior pubic ramus. This eminence gives attach- 

 ment to the ilio-pectineal intermuscular septum, and, it may be, 

 partial insertion to the psoas parvus. 



The posterior border extends from the posterior superior spine to 

 a point a little below the deepest part of the great sciatic notch, 

 where there is usually a faint transverse line on the external 

 surface, indicating the place of junction of the ilium and ischium. 

 Superiorly it presents the posterior interspinous notch, and below 

 this the posterior inferior spine, which gives attachment to the great 

 sacro-sciatic ligament, whilst immediately below this it gives 

 origin to fibres of the pyriformis. Inferiorly the posterior border 

 forms the upper part of the great sciatic notch, over which the 

 pyriformis passes as it leaves the pelvis. 



The external surface or dorsum ilii, concavo-convex from behind 

 forwards, is traversed by three ridges, called the superior, middle, 

 and inferior gluteal, or curved, lines. The superior gluteal line 

 commences at the outer lip of the crest about 2 inches in 

 front of the posterior superior spine, and passes downwards and 

 forwards to the upper part of the great sciatic notch. The surface 

 which it cuts off is semilunar, and its upper part is rough for the 

 origin of fibres of the gluteus maximus. The middle gluteal line 

 commences at the outer lip of the crest i^ inches behind the anterior 

 superior spine, and passes backwards and downwards to the upper 

 part of the great sciatic notch, where it terminates close to the 

 superior line. The surface included between the middle gluteal line, 

 crest, and superior gluteal line, which is falciform, gives origin to 

 the gluteus medius. The inferior gluteal line commences at the 

 lower part of the anterior interspinous notch, whence it passes back- 

 wards to the deepest part of the great sciatic notch. The space 

 between the inferior and middle gluteal lines gives origin to the 

 gluteus minimus. Between the front part of the inferior gluteal 

 line and the margin of the acetabulum there is a short transverse 

 groove, which gives origin to the reflected head of the rectus femoris. 

 The iliac portion of the bone is very thin and translucent toward 

 the upper part of the middle third, where it is sometimes perforated, 

 and it presents a strong rounded ridge, leading upwards from the 

 margin of the acetabulum to the tubercular eminence on the outer 

 lip of the crest. There is also a strong bar of bone extending from 

 the upper margin of the acetabulum to the auricular surface on the 

 internal aspect. 



The internal surface is divisible into an anterior, and a posterior, 

 portion. The anterior division, which represents two-thirds, is sub- 

 divided into a small lower, and large upper, part by the iliac portion 

 of the ilio-jjectineal line, the direction of which is forwards and down- 

 wards. The part below and behind the line enters into the lateral 

 wall of the pelvis, and gives origin to a portion of the obturator 

 internus. The part above the line is extensive and concave, and 



