38 THE SKELETON OF THE CAT. 



only by a small passageway lying within the joint between the 

 ends of the bones. The dorsal one is attached to the femur 

 several millimeters proximad of the patellar surface and some 

 distance on each side of the latter. The patella is imbedded 

 in its outer wall, and it is attached to the tibia on the edges of 

 the articular surface of the latter, from the crest to the tuber- 

 osities. The capsule is also attached laterally and medially to 

 the sides of the menisci, and is closely united to the patellar 

 ligaments. Its cavity contains a mass of yellow fat. 



The ventral capsule is attached to the borders of the articu- 

 lar surfaces of the femur and tibia on their ventral sides, to the 

 menisci, and to the epicondyles of the femur and the tuberosi- 

 ties of the tibia. Its walls are stronger and its cavity smaller 

 than those of the dorsal capsule. 



The ligaments of the knee-joint (Figs. 60 and 61), aside 

 from the capsules, may be classified into: (i) those which are 

 connected with the patella; (2) collateral ligaments (Fig. 60, 

 i andy), which pass from the epicondyles directly distad along 

 the sides of the joint to the tibia or fibula ; (3) crucial ligaments 

 (Fig. 60,^ and h\ Fig. 61 , rand d), which cross within the joint 

 from one side of the femur to the opposite side of the tibia ; (4) 

 ligaments which hold the menisci in place (Fig. 60, e and/; 

 Fig. 6\, e and/). 



(i) Ligaments of the Patella. — The patella is im- 

 bedded in the dorsal wall of the dorsal capsule of the joint. 

 From its distal end a strong tendon or ligament passes distad 

 to the crest of the tibia. This is known as the ligamentum 

 patellae: it may be considered a part of the tendon of M. quad- 

 riceps femoris. On the lateral side the capsule of the joint is 

 strengthened by the transverse fibres of the tendon of M. plan- 

 taris, which aid in holding the patella in place. 



(2) Collateral Ligaments. — Of these there are two. 

 The ligamentum collaterale fibulare (Fig. 60, / ) is attached to 

 the lateral epicondyle of the femur and passes distaci across 

 the tendon of the plantaris muscle to the head of the fibula. 

 Dorsad of the fibular ligament and parallel with it passes the 

 tendon of origin of the extensor longus digitorum. The liga- 

 mentum collaterale tibiale (Fig. 60, i; Fig. 61, g) begins on 



