THE SKELETON 31 



the head of the femur fits. The ilium is by 

 far the largest segment, and is joined firmly 

 to the transverse processes of that fused part 

 of the vertebral column which contains the 

 last thoracic, the lumbar, and the sacral 

 vertebrae. So long as there are prominent 

 spinous processes to the vertebrae, a thin plate 



I|. S.F. 



P. 



Fig. 7.— Left Hip-Bone. 



II., ilium ; S.F., sciatic foramen ; Is., ischium ; P., pubis ; A., acetabulum. 



of bone joins the ilium to them, and thus is 

 bounded a narrow canal between the ilium 

 and the fused spinous processes. The cranial 

 half of the outer surface of the ilium is in the 

 form of a deep concavity in which lie the 

 gluteal muscles, while the caudal half of the 

 same surface is convex. The inner surface 

 helps in the formation of a deep double con- 

 cavity in which the kidneys are lodged. 



