1. =A. suralis.=--This is a large branch which passes distad from the caudal side of the popliteal artery. It sends branches to the biceps and to the fat in the popliteal space, and passes onto the ventral border of the lateral head of the gastrocnemius. It sends branches to both heads of the gastrocnemius and to the popliteus, passes distad onto the lateral surface of the tendon of Achilles, and may be traced to the proximal portion of the dorsolateral side of the foot, where it sends many branches to the integument about the ankle-joint. It then passes along the lateral side of the foot and supplies the artery on the lateral side of the fifth digit. 2. =Aa. genu posteriores.=--Several small arteries which pass to the knee-joint. 3. =Rami musculares.=--Numerous small branches to the muscles about the popliteal space. 4. =A. tibialis posterior.=--This is the largest branch of the popliteal artery, which it leaves just before the latter passes beneath the popliteal muscle. The tibialis posterior passes at first mediad, then turns distad, passes across the popliteus muscle onto the surface of the flexor longus hallucis, and ramifies in the substance of this muscle and its tendon. It gives branches also to the gastrocnemius and soleus. (It does not pass into the foot as does the corresponding artery in man.) 5. =A. tibialis anterior.=--The anterior tibial artery is the continuation of the popliteal after its passage through the interosseous membrane between tibia and fibula to the dorsal side of the lower leg. Here it passes distad, lying against the interosseous membrane, between the extensor longus digitorum and the tibialis anterior muscle, or partly imbedded in the substance of the latter. It passes, lying beneath the tendons of these muscles, through the transverse ligament proximad of the malleoli, thus reaching the dorsum of the foot. It extends distad across the tarsus to the space between the second and third metatarsals, and through this space to the plantar side of the foot (Fig. 128). Here it receives one or two small branches (_a_ and _d_) from the plantar branch of A. saphena (forming with them the =plantar arch= (_c_)), and passing distad and slightly laterad, divides into three main portions (_e_). These (=Aa. digitales plantares=) pass to the three intervals between the digits. The medial one passes along the lateral side of the second digit; the next divides, sending a branch to the lateral side of the third digit and the medial side of the fourth; the lateral one passes along the medial border of the fifth digit. The Aa. digitales plantares send numerous branches to the interosseous muscles. [Illustration: FIG. 128.--DEEP ARTERIES ON THE PLANTAR SURFACE OF THE FOOT. _a_, medial twig from plantar branch of A. saphena; _b_, A. tibialis anterior (or plantaris profunda); _c_, plantar arch; _d_, lateral twig from plantar branch of A. saphena; _e_, terminal branches from A. tibialis anterior.]