324 



DR THOMAS W. SHORE. 



tiuiious. I am still engaged in the investigation in frog-tadpoles 

 of the fate of the posterior cardinals and their relations to the 

 post-caval, and have already satisfied myself that the posterior 

 part of the post-caval is formed from a portion of the posterior 

 cardinals, and that another part of them is connected with the 

 development of the renal portals. ]\Iy investigation is, however, 



— p.c.v. 



r.v.' 



r.r.p.v. 



r.v. 



l.r.p.v. 



Fig, 1. — Unusual renal portal vein, p.c.v., post-caval vein; r.v., renal vein ; 

 h, kidney ; r.r.p.v., right renal portal vein ; l.r.p.c, left renal portal vein ; 

 u, ureter. 



incomplete, and I hope to deal fully with this topic, and the 

 development of some other veins, in a future paper. 



2. A Vein coiineditig the Renal Portal and the Pulmonary. — 

 In another frog, I have found the very remarkable condition of 

 a vein of moderate size running forwards from the left renal 

 portal vein to join the left pulmonary on the root of the lung, 

 and receiving in its course a few small tributaries from the lung 

 itself. In this case some of the venous blood carried by the 

 renal portal was able to return to the heart vid the pulmonary 

 system, and independently of the post-caval system. The vein 



