1. =A. profunda femoris= (Fig. 126, _y_).--This is given off just before the external iliac leaves the abdominal cavity. It passes caudad, and about one centimeter from its origin it gives off three branches, sometimes all separately, sometimes two in common. One of these passes mediad in the lateral ligament of the bladder and ramifies on the lateral surface of that organ. A second passes through the abdominal wall and into the fat on the medial surface of the thigh; it sends a branch caudad toward the external genital organs, while its main trunk passes distad in the subcutaneous fat almost to the knee. From one of these two a small branchlet passes in the male to the spermatic cord and accompanies this to the testis; it represents thus the =external spermatic artery=. The third branch, =A. epigastrica inferior=, passes directly to the ventral surface of the rectus abdominis muscle, on which it passes craniad, sending branches to the muscles of the abdominal walls. It anastomoses with terminal branches of the internal mammary artery. The profunda femoris itself passes between the iliopsoas and the pectineus muscles, then to the medial surface of the adductor femoris. It divides into branches which supply the pectineus, adductor longus, adductor femoris, caudofemoralis, quadratus femoris, semimembranosus, and semitendinosus. [Illustration: FIG. 127.--SUPERFICIAL ARTERIES, VEINS, AND NERVES ON THE MEDIAL SIDE OF THE LEG. _a_, A. and V. femoralis; _b_, N. femoralis; _c_, A. profunda femoris; _d_, A. and V. circumflexa femoris lateralis; _e_, ramus muscularis; _f_, A. saphena and V. saphena magna; _g_, N. saphenus; _h_, A. and V. articularis genu suprema; _i_, N. tibialis; _j_, plantar branch of A. saphena; _k_, dorsal branch of A. saphena. 1, M. sartorius; 2, M. tensor fasciæ latæ; 3, M. rectus femoris; 4, M. iliopsoas; 5, M. pectineus; 6, M. adductor longus; 7, M. adductor femoris; 8, M. semimembranosus; 9, M. gracilis; 10, M. semitendinosus; 11, medial head of M. gastrocnemius; 12, M. plantaris; 13, M. flexor longus digitorum; 14, M. tibialis anterior; 15, tibia.]