234 ANATOMY OF THE RABBIT. 
Between the apposed surfaces of the condyles, in the interior of 
the joint, there are two short, cruciate ligaments and two thin 
plates of fibrocartilage, the medial and lateral menisci. The 
anterior cruciate ligament (lig. cruciatum anterius) passes from 
the lateral wall of the intercondyloid fossa of the femur to the 
anterior end of the intercondyloid eminence of the tibia. The 
posterior cruciate ligament passes from the medial wall of the 
intercondyloid fossa of the femur to the posterior intercondyloid 
fossa of the tibia. The medial meniscus (meniscus medialis), 
a thin crescentic plate of fibro-cartilage, lies on the articular surface 
of the medial condyle of the tibia, and is connected by ligament with 
the anterior and posterior intercondyloid fossae of the bone. The 
larger, lateral meniscus lies on the lateral condyle of the tibia, 
and is attached by ligament anteriorly to the medial portion of the 
articular surface, and posteriorly to the medial wall of the inter- 
condyloid fossa of the femur. The tendon of origin of the extensor 
digitorum communis traverses the anterior part of the joint on its 
way from the patellar surface of the femur to the front of the leg. 
The interosseous ligament of the leg (lig. interosseum cruris) forms an 
almost complete sheet connecting the uncoalesced portions of tibis and fibula. 
C. The ankle-joint (articulatio talocruralis) is a ginglymus with 
a considerable amount of spiral torsion. The articulating surfaces 
are chiefly formed by the tibia and talus, but also by the fibular side 
of the tibiofibula and the calcaneus. On the tibial side the calean- 
eotibial ligament (lig. calcaneotibiale) connects the medial 
malleolus with the sustentaculum tali. On the fibular side the 
calcaneofibular ligament (lig. calcaneofibulare) connects the 
posterior portion of the groove for the peronaei muscles forwards 
with the lateral surface of the calcaneus, and a second ligament 
extends from the anterior margin of the groove backward to the 
lateral surface of the calcaneus. The tibionavicular ligament 
(lig. tibionaviculare) connects the anterior surface of the distal 
end of the tibia with the dorsal surface of the navicular bone. The 
joint contains in its interior a short strong ligament connecting the 
medial side of the lateral malleolus with the lateral and ventral 
surfaces of the trochlea tall. 
