[Proc. Roy. Soc. Victoria, 31 (N.S.), Part 1., 1918]. 



AitT. III. — Abnormal Renal Portal Circulation of a Frog. 



By ALICE OSBORNE, B.Sc. 



(With Plate I. and one Text Figure). 

 [Read April 11th, 1918]. 



I must thank Dr. Buchanan, of the University of Melbourne, for 

 bringing this frog (Hyla aurea), showing an abnorm.al Renalportal 

 •circulation, under my notice. 



It is not an unconmion occurrence to find abnormalities in the 

 anterior veins, as well as in other parts of Hyla aurea; but varia- 

 tions in the portal systems are much less frequent. 



The abnormality under comment was seen in the Renal portal 

 system of the right side only — that of the left side being quit-e 

 normal and consistins: mainly of a double Renal portal vein. 



The Renal portal vein normally arises from the union of the 

 sciatic and the iliac veins. On the right side of this s/pecimen the 

 iliac vein was slightly longer, and tlie vein formed by the union 

 of the sciatic and iliac veins, which for convenience sake I shall 

 refer to as Renal portal, A, was a large vessel entering the lateral 

 edges of the kidney more anteriorly than did the Renal portal of 

 the left side. 



So far as the origin of the vessel, A, was concerned, it corre- 

 ■sponded exactly to the normal Renal portal vein, with, however, 

 one difference, viz., the dorso-lumbar vein instead of opening sepa- 

 rately and anterior to the Renal portal vein, in this case opened 

 •directly and somewhat backwardly into the vessel, A. 



In addition, there was another longitudinal vessel, Renal portal 

 Tein, B, opening into the kidney in a position corresponding to the 

 entrance of the left Renal portal vein into the left kidney. 



This Renal portal vein, B, arose in the dorsal wall of the pelvic 

 region, and had a dight connection along its length with a vessel 

 which arose from the dorsal pelvic region, and emptied its blood 

 into the inner side of the left Renal portal vein. 



The latter vessel occurs quite frequently, but appeared somewhat 

 •enlarged in this case. 



Between the right Renal portal veins A and B was a somewhat 

 •curious connection Y, the middle of which received branches from the 

 -deeper layers of muscle around the pelvic region. 



