24 MR, F. E. BEDDARD ON THE [Jan. 16, 



the whole of the mesonepliros, and as the blood-vessels arising 

 from the parietes do extend along at any rate very nearly the 

 whole of the mesonephros, as does the longitudinal vein into which 

 they pour their contents, it would appear that these suprarenal 

 afferent portals are also concerned with the blood-supply of the 

 mesonephros, vid the remains of the posterior cardinal. The 

 suprarenal portals are thus not veins especially destined for the 

 suprarenal circulation, but originally merely the paiietal branches 

 of the cardinal. On the left side I found only three of these 

 veins. 



Precisely the same series of modifications appear to have pro- 

 ceeded in the case of the liver and of the parieto-hepatic portals. 

 In the Anaconda for example, and for the matter of that in all 

 snakes, as it appears, that have been hitherto examined ana- 

 tomically, the portal vein extends along the liver nearly to its 

 anterior end. This is shown plainly in the figure of the 

 circulatory system of the Python given by Jacquart*. Into this 

 portal, which runs along the lower surface of the liver, open all 

 or most of the vessels bringing blood to the liver from the parietes. 

 In the same way in certain Lizards (for instance, Amphishcena, 

 Ophisaurus, and Hatteria) there are at least considerable traces 

 of the same forward extension of the portal. Finally we get the 

 stage which characterises the majority of the Lacertilia, so far as 

 existing knowledge allows us to say, in which the portal enters 

 the liver at its posterior extremity and is not continued forward 

 as a continuous trunk. In these lizards the parieto-hepatic portal 

 veins enter the liver directly, instead of indirectly through the 

 portal vein. 



Dorsal Parieto-hepaticVeins. — These veins are entirely developed 

 upon the left side of the body in both specimens. They are, as in 

 other snakes, very highly developed, and a great portion of the 

 blood of the whole body must be contained in them. I describe 

 them only in one specimen ; they appeared to be much the same 

 in the other. The first of these veins, advancing from behind 

 forwards, joins the portal vein about on a level with the extreme 

 end of the liver, one lobe of which reaches considei-ably further 

 back than the other. It is one of the largest of the dorsal parieto- 

 hepatic veins and on reaching the neighbourhood of the body- wall 

 divides into a f orwardly running and a backwardly running branch. 

 Just before this division the vein receives twigs from the stomach. 

 The backwardly rimning branch supplies seven intercostal spaces. 

 The forwardly running branch supplies nine intercostal spaces 

 before the second trunk arises which joins the portal vein just in 

 front of the end of the shorter liver-lobe. As in other snakes, the 

 portal vein runs superficially along the liver, giving off twigs right 

 and left to the liver itself and receiving the doi-sal parieto-hepatic 

 vessels. Of these vessels (see text-fig. 7, p. 23) I counted nine in 

 addition to the two that have already been described. At their 



* Ann. Sci. Nat. (4) iv. p. 321. 



