876 



MT!. ¥, G. PABSONS ON THE 



[Nov. i9, 



The posterior ligament consists only of vertical fibres which are 

 pierced by the large azygos artery. 



Laterally, behind the condyle on each side, the joint cavity 

 communicates with a bursa under the respective heads of the 

 gastrocnemius, while in each head of the gastrocnemius there is a 

 fabella. The two crucial ligaments have the human attachments, 

 but they are not connected together at all. The synovial 

 membrane of the ligamentum mucosum is continued back to the 

 crucial ligaments, so that it is impossible to pass a probe between 

 the ligamentum mucosum and the anterior crucial ligament as in 

 man. The semilunar cartilages are remarkable for having their 

 anterior parts ossified ; this is interesting when it is compared 

 with the condition of the orbicular ligament in the elbow, though, 

 as has already been pointed out, the animal was a fully adult, if 



Fig. 6. 



A.C. 



A.S 



Knee-joint of Fedetes from behind. 



A.C. & P.O. Anterior and posterior crucial ligaments. 

 E.S. & I.S. External and internal semilunar cartilages. 

 A.)S. Articular surface over which popliteus plays. 



not an aged specimen. The posterior attachment of the external 

 cartilage runs upward and inward, to be attached to the back of the 

 internal condyle ; it lies in a plane posterior to that of the posterior 

 crucial ligament and evidently corresponds to the oblique ligament 

 of Humphry of human anatomy (see fig. 6). The posterior part of 

 the external coronary ligament is the only part present, but the 

 internal semilunar cartilage has more or less of a coronary ligament 

 all round. The two cartilages are connected to the lateral ligaments 

 by loose connective tissue, so that they can move independently of 

 these. In extension of the joint there is a considerable portion of 

 the articular surface of the external tuberosity of the tibia behind 



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