1904.] CIRCULATOKY SYSTEM IX THE OPHIDIA. 361 



aorta, all of which supply the fat-body. The spermatic ai'tery 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 ofi" two branches to the fat-boclies. 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-fiir. 75. 



Testis and blood-supply of Naia tripiidians. 

 Ao., aorta; F.B., arteries to fat-bodies; T., anterior, T.', posterior testis. 



Gasti'ic 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 am disposed to regard them rather as supplying the peri- 

 toneum. There are three lai'ge gastric arteries, apai't from the 

 gastric branch of the supei'ioi- mesentei'ic. 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 gall- 

 bladder. Behind this aiteiy 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 pos- 

 terior than of the anterior kidney, thus exactly repeating the 



