OSTEOLOGY AND SYNDESMOLOGY. 41 
strong and important ligaments. The posterior or great sacro-sciatic ligament 
(pl. 125, fig. 5°) arises from the lower and back part of the posterior infe- 
rior spine of the ilium, and from the back part of the sacrum and coccyx ; 
it is inserted into the lower and inner edge of the tuber ischii, and by a 
falciform process into the ramus of the ischium. By its upper border it 
converts the lesser sciatic notch into a foramen, and by its lower it com- 
pletes the posterior and lateral boundary of the lower opening of the pelvis 
on each side. The anterior or lesser sacro-sciatic ligament ( fig. 5") crosses 
in front of the former; it arises from the side of the sacrum and coccyx, 
and is inserted into the spine of the ischium. It separates the two sciatic 
foramina. | 
The symphysis pubis (fig. 7) connects the vertical oval surfaces of the 
ossa pubis. It is covered in front by a thick fibrous tissue, called the ante- 
rior pubic ligament; the superior and posterior pulic ligaments strengthen 
it superiorly and posteriorly; the sub-pubic hgament is situated beneath the 
symphysis. 
2. THE IL1I0o-FEMORAL ARTICULATION, OR THE Hip Jornt ( pl. 126, figs. 6 
and 7). This is the strongest and most perfect enarthrodial, or ball and 
socket joint, in the system. It includes the head of the femur and the ace- 
tabulum, both of which are incrusted with cartilage, and is secured by a 
capsular and an accessory ligament, a synovial membrane, an inter-articular, 
cotyloid, and a transverse ligament. 
The iho-femoral capsular ligament arises from the os innominatum by a 
very strong attachment; passes downwards and upwards, incloses the 
cotyloid ligament, but does not adhere to it except at the notch; enlarges 
opposite the head of the femur, then becomes flattened and contracted to 
embrace the cervix, the greater part of which it incloses. Its insertions 
into the upper part of the femur are partly into the bone, and partly into 
the periosteum. 
The accessory or ilio-femoral ligament is a strong fibrous band, incorpo- 
rated with the capsular, arising from and around the spinous process of the 
ilium, and is inserted into the anterior inter-trochanter line, near the lesser 
trochanter. 
The synovial membrane is exposed by dividing the capsular ligament, 
whose internal surface it lines to some extent. | 
The cotylowd ligament ( fig. 7*) is the fibro-cartilaginous lip which deepens 
the acetabulum, and at the same time narrows its orifice, so as to hold the 
head of the femur even after the capsular ligament and all the muscles have 
been divided ; it fits so tightly around it that the head appears to be retained 
in the socket partly by atmospheric pressure. The transverse ligament con- 
sists of ligamentous bands, passing across the notch in the border of the 
acetabulum, and completing the margin of the cavity. 
The inter-articular or round ligament, ligamentum teres (fig. 7°) arises by 
two flat bands from the margins of the cotyloid notch, runs upwards, back- 
wards, and outwards, and is inserted into the depression on the head of the 
femur. 
3. THE FEMORO-TIBIAL ARTICULATION, OR THE KNEE JOINT. The con- 
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