388 MR. F. E. BEDDARD OX THE [Feb. 16, 



the 1st and 2ncl intercostal aiteries ; the second accompanies the 

 4th ; the third and fourth the 7th and 8th respectively ; the fifth 

 arises between arteries 9 and 10 ; the sixth accompanies the 14th 

 and 15th. The next two intercostal hepatic portals correspond 

 to the 7th aiad 10th intercostal arteries of the second series*. 



The ninth and tenth parietal veins arise respectively close to 

 the 25th and the 28th and 29th intercostal arteries ; the tenth 

 vein is formed by the union of two trunks. These vessels are 

 connected with the testis. They arise from the right side. Some 

 way behind them are two veins for the postei'ioi-ly situated testis, 

 which arise from the paiietes on the left side of the dorsal middle 

 line. 



Mood-vessels of vent7-al parietes. — These vessels, which are 

 numerous, are of course the equivalents of those of the anterior 

 abdominal system in other Vertebrates. The first of them arises 

 just opposite the 2nd intercostal artery 4 inches behind the 

 heart. Several are accompanied by an epigastric artery, and 

 along the ventral median line lies a continuous epigastric artery 

 and vein of which these are branches. The first 9 of these veins 

 open directly into the liver; they ai'ise from the longitiidinal 

 trunk by one root or by several. A strongish arteiial twig 

 derived from the artei-ial plexus upon the oesophagus accompanies 

 the first vein ; but the remaining 8 have not at least a well- 

 marked arterial companion. The longitudinal epigastric arteries, 

 moreover, are slender in this region ; there are two of them, one 

 running on either side of the median vein ; occasionally the artery 

 breaks up into a plexus. Just before the ninth vein the epigastric 

 arteiy of the right side increases in size and is shortly reinforced 

 by the first of a series of post-hepatic epigastric branches. This 

 first branch is the most prominent of the seiies. It is not asso- 

 ciated with a vein, and divides before reaching the middle line 

 into an anterior and a posterior branch. From the end of the 

 hepatic series to the cloaca I counted 35 veins, which should 

 possibly be reduced by 2, inasmuch as 2 of the veins in question 

 were formed by the junction of two veins each. As to arteries, 

 I counted 24 after the particularly well-developed one to which 

 attention has just been called, and these for the most part were 

 accompanied by veins. The number is probably understated, 

 owing to inefficient injection posteriorly. The agreement with 

 the corresponding veins is often very close, the artery bifurcating 

 at the same time that the vein bifurcates, 



Zamenis flagelliformis. 



The 9-ight aortic arch divides, of course, into the aorta and an 

 anteriorly running trunk, the anterior vertebral artery. Of these 

 two branches the vertebral is the more important, and the aoi-tic 

 tiumk joins it as if it were a branch entering it from behind, 

 rather than if the vertebral were itself a bi'anch of tlie aorta. 



* See p, 333. 



