694 MAMMALIAN ANATOMY 



is more prominent than the outer ridge, and the external lateral liga- 

 ment is inserted into a distinct pit' on the tuberosity behind the centre. 



The articular surface on the distal and posterior side of the con- 

 dyle (Figs. 532, 533) is narrower than the outer surface, and begins 

 without a distinct line of separation at the lower part of the trochlea. 

 It is directed at first inward as well as backward ; it then becomes 

 wider, and, with almost parallel borders, curves upward and outward. 

 It is more evenly convex than the external articular surface, and does 

 not face so much toward the intercondyloid notch. 



The trochlea (Fig. 533) is a linear, grooved, articular surface con- 

 tinuous with the anterior surface of the shaft of the femur ; it arches 



FIG. 533. 



Anterior Surface. 



/EXTENSOR LONGUS DIG1TORU.M. 



Trochlea for Patella.- 



Posterior Crucial Ligament ; ,l-^/ Lateral Li gammt . 



inner Tuterosity.^ ' ' 



/ """' ''"'"''"'' X^VJ? ^aHJT'o^f, Connie. 



w 



Intercondyloid Notch. POPLITEUS 



LEFT FEMUR, DISTAL SURFACE. 



downward and backward, passes at the sides, without distinct limitation, 

 into the articular surfaces on the outer and inner condyles, and ends 

 abruptly in the middle line at the front part of the intercondyloid 

 notch. Its upper margin is arcuate ; the outer end of the curve is 

 slightly higher than the inner end. The lateral borders are promi- 

 nent, straight, and parallel. The articular surface of the trochlea is 

 about twice as long as wide, strongly convex from above downward, 

 and concave from, side to side. It articulates with the posterior surface 

 of the patella. 



The intercondyloid notch (Figs. 532, 533) lies at the lower and 

 posterior part of the lower extremity of the femur, between the con- 

 dyles. It is more than twice as long as it is wide, sharply limited in 

 front from the trochlea and at the sides from the condyles ; above, it 

 is separated by a transverse ridge from the lower part of the popliteal 

 space. 



It is concave from side to side and convex from above downward. 



