1904.] CIRCULATUllY SYSTEM IX THE OPHJBIA. 357 



two trunks, of which one runs sti-aight forward to the f ui'ther 

 side of the stomach, while the other branch immediately divides 

 into two main branches which supply the nearer of the two 

 longitudinal gastric arteries ; these also give off arteiies to the 

 fat-body. Arteries 3 and 5 cross the stomach and pass at once to 

 the further of the two longitudinal arteries ; there is no branch 

 to the nearer. The 4th and 6th are like the 1st and 2nd, in that 

 they supply both the gastric longitudinal vessels. The 6th artery 

 is not markedly larger than the 4th. The gastric branch of the 

 superior mesenteric divides into two trunks, each of which 

 supplies one of the two longitudinal trunks of the stomach. It 

 is to be noted that the spleen, gall-bladder, &c. are not supplied 

 with blood from the last gastric artery, but only from the superior 

 mesenteric. This contrasts with the condition observable in some 

 other snakes. 



Sioermatic Arteries. — There is but a single spermatic artery to 

 each testis. The first of these is the first viscei-al branch of the 

 aorta after the superior mesenteric. It reaches the testis at its 



lliglit testis of Opliiopliagiis ;iiid its blood-supply. 



^0., aorta; JF.J?., fat-body artery; l.C, intercostal artery; I}it., intestinal 

 artery ; Ji.., kidney ; Sp.A., spermatic artery ; Sr.p., su2n'arenal portal 

 vein ; T., testis ; V.c.L, vena cava. 



posterior end, where it is nearly in contact with the kidney. At 

 this point the spermatic artery gives ofi" a branch to the kidney. 

 The spermatic artery runs along the kidney anteriorly on the 

 opposite side to the vena cava, giving off branches to its substance 

 (see text-fig, 72). It also gives off two branches, which supply 

 adjacent viscera : firstly, a stouter biunch to the fat- body ; secondly, 

 a more slender branch wdiicli supplies both fat-body and intestine. 

 Close to the spermatic arteiy runs a portal vessel to the supra- 

 renal. It emerges fi-om the parietal on the right of the middle 

 line by three roots. The posterior testis, which is considerably 

 the smaller, has also one spermatic artery. This gives a branch 

 to the intestine before it reaches the testis, and later two branches 



