THE I'KLl'lS. 



S 



Each coxa, as has been stated, is composed of three portions whicli 

 unite at the acetabuhnn ; and although consoHdated into one piece, yet 

 they are separately described as if distinct. The names of these divi- 

 sions are ilium, ischiian, a.nd jyu bis. 



Ilium. — The ilium, hip, or liaunch hone (as ilium), frives its name to 

 the region it occupies. It is the largest of the three bones, as well as 

 being that which is most elevated. In shape it is irregularly triangular 

 and tlat, and is directed obliquely downwards, inwards, and backwards; 

 it has two faces, three borders, and three angles. Its cvteniai or superior 

 face, or dorsum, is marked by some muscular imprints, and is curved in 

 its widest part to form a concave space — the external iliac fossa, which 

 lodges the gluteal muscles. The internal or inferior face, or venter, 

 offers a smooth external portion — the iliac surface, into which is im- 

 planted the iliac psoas or iliacus muscle ; and an internal roughened, 



Fig. 1. 



Pelvis ok thk Mare 



A, Ilium ; 13, I'ubia ; C, Ischium ; D, Foramen Ovale ; E, Tuberosity of the 

 Ischium ; F, Cotyloid Cavity. 



ear-shaped, irregularly diarthrodial surface, most apparent from behind 

 --the auricular facet, for articulation with the sacrum. 



The anterior border, or crest of the ilium, is slightly concave, and bears 

 a rugged lip for muscular insertion. The external border is thick and 

 roughened, and grooved for the passage of bloodvessels ; inforiorly it 

 has three nutrient foramina. The internal border is thin and concave, 

 especially in its posterior part, where it constitutes the (jreat sciatic 

 notch ; it affords attachment to the sacro-sciatic ligament. The spine 

 or ridge of the same name partly belongs to it. 



The external angle, antcro-supcrior spinous jyrocess, or point of the hip, 

 is a wide, thick, and flattened portion, bearing four tuberosities afford- 

 ing attachments to muscles. The internal or antero-intcrnal angle or 

 supero-posterior spinous process, is a rough tuberosity curving upwards 

 and backwards to form an angle with the corresponding portion of the 

 opposite ilium — the sumtnit of the croup. The inferior, posterior or coty- 

 loid angle (concurring in the formation of the acetabulum), is very large 



