The Lower Extremity and Pelvis 



135 



The pubic arch is below the symphysis ; the sub-pubic ligament stretches across 

 below the lower and back aspect of the two bones. The penis turns down from its root 

 about the level of the lower part of the symphysis in the horizontal plane, but its level 

 in planes drawn at right angles to the front of the bones is much higher, the upper line 

 of the curve, almost reaching the plane of the top of the symphysis : this is owing, of 

 course, to the obliquity of the bone. The clitoris, in the same way, reaches about one 



FJG. 112. On the left somewhat exaggerated outlines of differences in 

 the posterior borders of male and female bones, showing the more 

 angled notch in the former. On the right the sexual differences are 

 illustrated in the pubic region ; observe that the wider female arch is 

 correlated with a longer pubis, and this, with the relatively smaller 

 acetabulum, makes the breadth of the acetabulum less than the 

 distance between it and the symphysis. Notice the pubic angle formed 

 with the vertical plane. 



quarter to half the distance up, and the lower edge of the symphysis is only a little in 

 front of the urethra in women. 



Ischio-pubic Margin. This has been already considered : observe the hinder part, 

 where there is an outer slope occupied by the origin of Adductor magnus, and an inner 

 one in relation with ischio-rectal fatty tissue. This region is also epiphysial, possibly 

 a traction epiphysis, but more probably one of the atavistic variety, representing a 

 remnant of the hypoischium of birds and reptiles. 



Back of Tuberosity of Ischium : facets, upper and outer for Semimembranosus 

 and lower and inner for Biceps and Semitendinosus, are well marked, and the latter 

 is closely bordered by the attachment of the great sciatic ligament, from which the 



