| OCR Text |
Show 1904.] CIRCULATORY SYSTEM IX THE OTHIDIA. 361 aorta, all of which supply the fat-body. The spermatic artery of the posterior testes is actually the next artery to arise from the aorta; it is immediately followed by a second artery. That the posterior testis has two arteries, while the anterior has only one, is remarkable since the posterior gonad is the smaller of the two. The first artery enters the gonad at the posterior end, which is also the case with the anterior spermatic artery ; it runs forward and gives off two branches to the fat-bodies. The second spermatic artery really supplies the vas deferens, and a little farther back along the aorta a third vessel rises. All the arteries of the gonads and their ducts are thus close together. Text-fig. 75. Ac Testis and blood-supply of Naia tripudians. Ao., aorta; F.B., arteries to fat-bodies; T., anterior, T.', posterior testis. , Gastric and Intestinal Arteries.-The gastric arteries are, as in some other snakes, divided into two series of* larger vessels and minute vessels, between which there are none of intermediate size. The minute vessels end' upon the surface of the stomach, but I a m disposed to regard them rather as supplying the peritoneum. There are three large gastric arteries, apart from the gastric branch of the superior mesenteric. The first one is much smaller than the two which follow; these latter are about equi-sized. The first two are closer together than is the second to the third ; the second and the third are about as far apart as is the third from the superior mesenteric. They form, as is usual, two longitudinal trunks running one on each side of the stomach. The second and third are connected with both longitudinal trunks, but the first appears to be connected only with that of the left side. The superior mesenteric artery arises at the commencement of the coiled part of the intestine and some way behind the gallbladder. Behind this artery there are three which supply the alimentary canal. They lie among the renal arteries, of which two lie in front of the inferior mesenteric. The renal arteries are more numerous in the case of the posterior than of the anterior kidney, thus exactly repeating the |
