624 MR. F. E. BEDDARD ON THE [May 29, 



these unite some little way before they reach the liver. Shortly 

 after reaching the liver, but before burying itself in the substance 

 of the same, the vein receives another which is made up of three 

 tributaries, of which two are from intercostal spaces immediately 

 following those which give rise to the first two of these dorsal 

 parieto-hepatic branches. The third vessel arises from the 

 pai-ietes laterally. The vein formed by the union of the five venous 

 twigs which have been just enumerated enters the substance of 

 the liver considerably to the right of the entrance of the right 

 anterior abdominal vein. Between the two enters a vein which 

 conducts only blood from the lateral parietes. As is also shown 

 in the figure referred to, the posterior vertebral artery arises 

 from the aorta and reaches the parietes between the two anterior 

 intercostal veins. This is the same on both sides of the body. 



These branches from the azygos to the liver are also arranged 

 with perfect symmetry in relation to each series on the two sides 

 of the body. They commence in each case opposite to the same 

 vertebiu. The actual sizes, however, of the several branches difier, 

 though the total volume appears to me to be much the same. On 

 the left side there are two thick trunks which are not far short of 

 the azygos itself in calibre. These join before reaching the edge 

 of the left lobe of the liver. After joining, the common trunk 

 bifurcates into a wider and a narrower branch. The wider branch 

 enters the liver at the apex of the left lobe immediately. The 

 narrower branch receives almost at once a thinnish parietal branch, 

 and passes downwards along the free posterior edge of the left liver- 

 lobe to some way along that margin, though considerably short of 

 the middle line. Here it enters the liver- substance independently 

 of not only the anterior abdominal vein, but also of the lateral 

 parietal and considerably to the left of both these veins. The wide 

 calibre of these various veins contrasts with the very narrow 

 corresponding intercostal arteries and their branches. This 

 contrast is much more marked than in other regions of the 

 vascular system, where the arteries and veins are more equisized. "; 



I have examined only one individual of Crococlilus cataphractxis, 

 and it might therefore be supposed that the conditions observed 

 being subject to variation were hardly distinctive of the species. 

 Whether this be so or not I do not, know ; but in any case there 

 is so considerable an agreement between two individuals of 

 Osteolcemus tetrasjns of which I have dissected the veins vmder 

 consideration, that I describe the following conditions with some 

 confidence as distinctive of that species. On the left side of the 

 body there are four vessels belonging to the system of veins which 

 is at present dealt with. The three anterior of these belong 

 entirely and only to the A^ena vertebralis posterior, and they arise 

 from it. The actual way in which these vessels join and rejoin 

 with each other before reaching the liver is illustrated in the sub- 

 joined figure (text-fig. 105, p. 621), and is rather more complicated 

 than the arrangement found in Crocodilus cataphractus and 

 (7. acutv.s ; that is to say, there are anastomoses between the trunks 



