SANGUIFEROUS SYSTEM. 513 



chord ; the ischiatic, principally to the muscular parts around 

 the anus ; and the pudic, which commonly affords branches 

 to the uterus, the bladder, and the external parts of genera- 

 tion. The external iliac artery (142. A. x. #.), before escap- 

 ing from the pelvis, through the crural arch, to become the 

 femoral, gives off the epigastric which sends branches to the 

 peritoneum, the scrotum, and adjacent parts, and establishes 

 anastomoses with the internal mammary and the inferior 

 inter costals ; and the circumflex ilii, which supplies chiefly 

 the anterior muscular parietes of the abdomen. The femoral 

 artery, after furnishing several small branches chiefly to the 

 muscles of the groin and lower part of the abdomen, gives off 

 the large profunda femoris, which is extensively ramified on 

 the powerful muscles of the thigh ; and becoming popliteal 

 behind the knee, the trunk divides, at a variable distance 

 below that joint, into the great anterior and posterior tibial 

 arteries, which descend, ramifying to the toes, like the radial 

 and ulnar arteries of the arm. 



The femoral artery divides higher in the ruminantia, 

 and the two tibials anastomose behind the first pha- 

 langes of the foot. The branches which supply the legs 

 of the ornithorhyncus, appear to be derived chiefly from 

 the internal iliacs. The femoral artery in the plantigrade 

 carnivora, divides into the two tibials, near the upper 

 part of the thigh, and the posterior tibial forms the 

 internal and external plantar arteries, below the middle of the 

 tibia. In most of the lower nocturnal quadrumana, the fe- 

 moral artery divides nearly as high as the crural arch, and its 

 branches subdivide into anastomosing plexuses, as on the 

 anterior extremities ; and this subdivision into minute plexi- 

 form branches, takes place to a greater extent in the femoral 

 arteries of the sloths and ant-eaters. The external iliac, in 

 many orders of mammalia, gives origin to the ilio- lumbar ar- 

 tery, and the profunda femoris to the epigastric. The epi- 

 gastric in the tiger arises from the internal iliac. In the 

 large tailed quadrupeds, as the otter, the external iliacs are 

 but moderate branches, from the great prolonged aorta, 

 which, after giving off, as in most other mammalia, the in- 

 ternal iliacs separately, continues its course backwards under 

 the bodies of the coccygeal vertebree, sending off regular pairs 

 of transverse branches at the vertebral articulations, like the 

 intercostal and lumbar arteries of the thorax and abdomen. 



PART VI. L L 



