PELVIC 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 ligamentum 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, ¢ and d; Fig. 61, a and 4), 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 
