240 THE SKELETON. 



almost vertically upwards to the base of the great trochanter ; the middle one, 

 the least distinct, is continued to the base of the trochanter minor ; and the 

 internal one is lost above in the spiral line of the femur. Below, the linea 

 aspera divides into two bifurcations, which inclose between them a triangular 

 space (the popliteal space), upon which rests the popliteal artery. Of these two 

 bifurcations, the outer branch is the most prominent, and descends to the 

 summit of the outer condyle. The inner branch is less marked, presents a 

 broad and shallow groove for the passage of the femoral artery, and terminates 

 in a small tubercle at the summit of the internal condyle. 



To the inner lip of the linea aspera, along its whole length, is attached the 

 Yastus Internus ; and to the whole length of the outer lip, the Vastus Externus. 

 The Adductor Magnus is also attached to the whole length of the linea aspera, 

 being connected with the outer lip above, and the inner lip below. Between 

 the Vastus Externus and the Adductor Magnus are attached two muscles, viz., 

 the Gluteus Maximus above, and the short head of the Biceps below. Between 

 the Adductor Magnus and the Yastus Internus four muscles are attached: the 

 Iliacus and Pectineus above (the latter to the middle of the upper divisions) ; 

 below these, the Adductor Brevis and Adductor Longus. The linea aspera is 

 perforated a little below its centre by the nutrient canal, which is directed 

 obliquely upwards. 



The two lateral borders of the femur are only slightly marked, the outer one 

 extending from the anterior inferior angle of the great trochanter to the anterior 

 extremity of the external condyle ; the inner one from the spiral line, at a point 

 opposite the trochanter minor, to the anterior extremity of the internal condyle. 

 The internal border marks the limit of attachment of the Crureus muscle 

 internally. 



The anterior surface includes that portion of the shaft which is situated 

 between the two lateral borders. It is smooth, convex, broader above and 

 below than in the centre, slightly twisted, so that its upper part is directed 

 forwards and a little outwards, its lower part forwards and a little inwards. To 

 the upper three-fourths of this surface the Crureus is attached ; the lower fourth 

 is separated from the muscle by the intervention of the synovial membrane of 

 the knee-joint, and affords attachment to the Subcrureus to a small extent. 

 The external surface includes the portion of bone between the external border 

 and the outer lip of the linea aspera ; it is continuous above, with the outer 

 surface of the great trochanter; below with the outer surface of the external 

 condyle : to its upper three-fourths is attached the outer portion of the Crureus 

 muscle. The internal surface includes the portion of bone between the internal 

 border and the inner lip of the linea aspera ; it is continuous, above, with the 

 lower border of the neck ; below, with the inner side of the internal condyle : 

 it is covered by the Yastus Internus muscle. 



The Lower Extremity, larger than the upper, is of a cuboid form, flattened 

 from before backwards, and divided by an interval presenting a smooth depres- 

 sion in front and a notch of considerable size behind, into two large eminences, 

 the condyles (XOI/SDXOJ, a knuckle). The interval is called the intercondyloid notch. 

 The external condyle is the more prominent anteriorly, and is the broader both 

 in the antero-posterior and transverse diameters. The internal condyle is the 

 narrower, longer, and more prominent internally. This difference in the length 

 of the two condyles is only observed when the bone is perpendicular, and de- 

 pends Tipon the obliquity of the thigh-bones, in consequence of their separation 

 above at the articulation with the pelvis. If the femur is held obliquely, the 

 surfaces of the two condyles will be seen to be nearly horizontal. The two 

 condyles are directly continuous in front, and form a smooth trochlear surface, 

 the external border of which is more prominent, and ascends higher than the 

 internal one. This surface articulates with the patella. It presents a median 

 groove, which extends downwards and backwards to the intercondyloid notch ; 

 and two lateral convexities, of which the external is the broader, more 



