The _ligamentum intero-laterale genu_ extends from the outer surface of the internal condyle of the tibia, or condylus internus tibiæ. It gives off a thin ligamentous slip which enters the joint and is attached to the inner half-moon shaped pad of fibrous cartilage, or meniscus, which it draws backward by the flexion of the knee (Fig. 16, No. _B_, 2). The _ligamentum popliteum_ arises from the fossa poplitea of the distal extremity of the femur and extends downward to the posterior rim of the head of the tibia. The _anterior ligamentum cruciatum genu_ originates from the fossa poplitea and extends outward antero-laterally to the rim of the head of the tibia (Fig. 25, No. 6). The _posterior ligamentum cruciatum genu_ is a short, strong ligament which originates from the cavity of the internal condyle of the femur, or condylus internus femoris, and inserts into the internal glenoid cavity of the tibia (Fig. 25, No. 1) or cavitas glenoidalis interna. The meniscus of the femoro-tibial articulation is divided into four parts, as follows: first, the _internal adhesio cornu antici cartilaginis lunatæ_; second, the _posterior adhesio cornu antici cartilaginis lunatæ_; third, the _external cornu cartilaginis lunatæ_; fourth, the _anterior cornu antici cartilaginis lunatæ_. The latter originates between the condyles and passes around the ligamentum cruciatum genu posticum (Fig. 16, No. _B_, 7). The inner semi-lunar fibrous cartilage is well developed and is joined by two ligaments between the femoral and the tibial surfaces (Fig. 25, No. 1). The external semi-lunar cartilage lies in a cavity between the external femoral condyle and the head of the fibula (Fig. 25, No. 2). The fibrous cartilages are bound posteriorly by a ligament, and by a second ligament to the head of the fibula, or capitulum fibulæ. Both pads of fibrous cartilage are connected by a transverse ligament called the _ligamentum transversale commune_ (Fig. 25, No. 5). The patella is provided with several ligaments, as follows: The _anterior patellar ligament_, broad, strong, and irregular in thickness, extends from the inferior margin of the patella to the rim of the second tibial crest (Fig. 16, No. _B_, 3). The _ligamentum capsulare capituli fibulæ_ is spread out between the head of the fibula, or capitulum fibulæ, and the superficies glenoidalis peronea tibiæ. [Illustration: FIG. 17.—Muscles and tendons of the head and posterior extremity. _A._ Section of neck with superficial muscles removed. 1, Obliquo-transversales. 2, Interspinales. 3, Intertransversales. 4, Interarticulares.