146 



PROF. W. N. PARKER, ON THE LEFT POSTERIOR [Mar. 19, 



the corresponding precaval, while posteriorly it opens into the 

 postcaval just at the anterior border of the kidneys, sending an 

 anastomosing branch to the renal portal. Professor Howes informs 

 me that he has since come across another Frog in which a similar 

 arrangement occurred, except that the azygas here entered the 

 subclavian instead of the precaval. 



A week or two ago, while examining a number of specimens of 



Fig. 1. 



pr.c. 



ur. 



The venous system of an acliilt male Frog (Rmia temporaria), in whicli the left 

 posterior cardinal vein persisted, and the postcaval was absent. From 

 the ventral aspect, X 2. 



cd, left cardinal vein ; h.v, hepatic veins ; /t, kidney ; Ir, liver ; pr.c, pre- 

 caval ; r.cd, vessel formed by the union of the posterior part of the two 

 cardinals, and which normally gives rise to the inter-renal portion of the 

 postcaval; r.p, renal-portal vein; ?M', revehent renal veins ; ^/j, sper- 

 matic veins ; s.v, sinus venosus ; ur, ureter ; v.s, vesicula seminalis. 



Bana temporaria during a class demonstration, I found that in one of 

 them (a male) the embryonic state of the veins was retained to a 

 still greater extent than in the cases quoted above (see fig. 1). A large 

 vein {cd), having similar relations to that described and figured by 



