PRLyiC LIMBS. 87 



border of the ilium to the sides of the sacrum. This is indis- 

 tinctly subdivided into several bands, which together represent 

 the long and short posterior iliosacral ligaments of man. 



Symphysis pelvis. — The medial borders of the pubis and 

 ilium meet in the middle line ventrad of the pelvis and are here 

 united by cartilage. The joint is strengthened by numerous 

 small bands which pass across the line of junction from one side 

 to the other; these occur on both surfaces. 



The Hip-joint. — The hip-joint is an enarthrosis, or ball- 

 and-socket joint in which more than half the spherical head of 

 the femur is received into the acetabulum. The depth of the 

 acetabulum is increased by a rim of fibrocartilage about its 

 margin, forming the labrum glenoidale. This passes across 

 the acetabular notch, forming the transverse ligament of the 

 acetabulum ; beneath it blood-vessels and nerves pass into the 

 acetabular cavity. 



The capsule of the joint is large and loose. It is attached 

 about the margin of the acetabulum, and passes over the head 

 of the femur, to be attached to the bone several millimeters 

 distad of the head. It thus encloses both the head and the 

 neck of the femur. 



The ligameutum teres, or round ligament, is a very strong, 

 short ligament which passes from the depression in the head of 

 the femur to the bottom of the acetabulum. 



The Knee-joint (Figs. 60 and 61). — The joint between the 

 femur and the tibia is very complex. The surfaces of the con- 

 dyles of the femur do not correspond to those of the condyles 

 of the tibia. Between the ends of the two bones are placed 

 two disks of cartilage, the menisci, or semilunar cartilages 

 (Fig. 60, c and d\ Fig. 6\, a and b), of such a form that the 

 congruity of articular surfaces is restored. Each meniscus has 

 a proximal surface corresponding to the form of one of the 

 condyles of the femur, and a distal surface' corresponding to a 

 condyle of the tibia. The menisci are held in position by liga- 

 ments. The knee-joint permits not only backward and forward 

 movement, but also a small amount of rotary motion. 



The joint has two capsules, one on the dorsal (convex) 

 side, the other on the ventral side. The two communicate 



