112 OUTLINES OF EQUINE ANATOMY. 



and decrease in size to form a tliin edge at tlie internal 

 margin around wliich the synovial membrane is reflected 

 from the upper to the under surface ; to the outer 

 margin the capsular ligament is firmly attached. The 

 anterior extremity of each cartilage is attached by a liga- 

 ment to the anterior part of the spine on the upper ex- 

 tremity of the tibia. The posterior extremity of each by 

 a ligament to the upper extremity of the tibia behind the 

 spine, but the outer cartilage in addition has a ligament 

 extending to the posterior part of the inter-condyloid 

 fossa of the femur. The femur is also connected to the 

 tibia directly by the crucial and the lateral ligaments. 

 The crucial ligaments, two in number, can only be exposed 

 by removal of one of the condyles of the femur. One 

 of them runs from the anterior part of the groove on the 

 tibial spine, to become attached supero- posteriorly to the 

 inner surface of the outer condyle in the intercondyloid 

 fossa ; its fibres cross at right angles, the other crucial liga- 

 ment, which runs from the anterior part of the intercondy- 

 loid fossa downwards and backwards to the superior ex- 

 tremity of the tibia behind the spine. 



The Older lateral ligament is superiorly attached to the 

 depression on the outer surface of the outer condyle of the 

 femur ; it crosses the tendon of popliteus which plays 

 through a sheath between this and the capsular ligament, 

 and then passes on to the femur. This ligament becomes 

 attached below to the upper extremity of the fibula ; from it 

 peroneus mainly arises. 



The inner lateral ligament is lomgeY smd narrower than the 

 outer, extending from the internal surface of the inner 

 condyle downwards to the supero-internal j^art of the tibia. 



The patella is connected to the femur by two lateral 

 ligaments. The inner extremity of the patella is continued 

 as a piece of fibro-cartilage which plays over the inner 

 condyle, and from this the inner ligament runs to the inner 

 surface of the internal femoral ridge. It is smaller than 

 the outer, which runs from the outer extremity of the 

 patella to the corresponding part of the outer ridge. 



The patella is connected to the tibia by three straight 

 ligaments. The inner runs from the complementary car- 

 tilage on the inner side of the patella to the supero-internal 

 angle of the ridge on the antero- superior part of the tibia. 

 The outer, which is composed of two portions, extends from 



