100 



BONES OF THE LOWER LIMB. 



posterior wall being prolonged in that direction by the integuments of the 

 perineeum. 



Differences according to Sex. The size and form of the pelvis differ 

 remarkably in the two sexes. In the female the constituent bones are 

 more slender and less marked with muscular impressions ; the perpendicular 

 depth is less, and the breadth and capacity greater ; the ilia are more ex- 

 panded than in the male ; the inlet of the true pelvis is more nearly circular, 

 the sacral promontory projecting less into it, and is broader from side to 

 side ; the depth of the symphysis pubis is less, the pubic arch is much 

 wider, and the space between the tuberosities of the ischia greater. 



The average dimensions of the pelvis, as measured in a number of full- 

 sized males and females, may be stated as follows, in inches : 



THE FEMUK. 



The femur or thigh bone, the largest bone of the skeleton, is situated 

 between the os innominatum and the tibia. In the erect position of the 

 body it inclines inwards and slightly backwards as it descends, so as to 

 approach inferiorly its fellow of the opposite side, and to have its upper 

 end a little in advance of the lower. It is divisible into a superior ex- 

 tremity, including the head and neck and two eminences called trochanters, 

 the shaft, and an inferior extremity expanded into an external and an in- 

 ternal condyle. 



At the superior extremity of the bone, the neck extends inwards and 

 upwards, and has a slight inclination forwards from the shaft. It has a 

 constricted appearance, and its diameter from before backwards is less con- 

 siderable than in the vertical direction, in which last greater strength is 

 required to sustain the weight of the body. Its superior surface is shortest ; 

 its inferior surface longest, and the anterior shorter than the posterior. The 

 head, forming more than half a sphere, covered with cartilage in the fresh 

 state, surmounts the neck, and is articulated with the acetabulum. Beneath 

 its most prominent point is a small depression or pit, which gives attach- 

 ment to the round ligament of the hip joint. 



The trochanter major is a thick truncated process prolonged upwards in 

 a line with the external surface of the shaft. In front it is marked by the 

 insertion of the gluteus minimus ; externally an oblique line directed down- 

 wards and forwards indicates the inferior border of the insertion of the 

 gluteus medius muscle, and lower down a horizontal line, continued upwards 

 in front of the trochanter, marks the upper limit of the vastus externus. 



