367 



the secretory epithelium iD both liver and kidney. (Lewis, Minot, 

 Shore and Shore and Jones.) 



3) Hsemoglobinurea is most easily produced in normal frogs by 

 renal-portal injection. (Adami.) 



4) After complete ligature of the arterial supply to the kidney 

 sub-cutaneous injections of diuretics produce a flow of urine. (Bain- 

 bridge and Beddard.) 



5) Ligature of the renal portal supply of one kidney reduces the 

 flow of urine therefrom, while the flow of the other remains normal. 



(GURWITSCH.) 



6) Renal portal perfusions, after complete ligature of the renal 

 arterial supply, produce a secretion of urine. (Cullis.) 



7) Arterial perfusions (not of urea) produce a flow of urine, the 

 urea of which must come from the blood of the portal supply. (Cullis.) 



It seems to me that the only conclusion to be drawn from a con- 

 sideration of the foregoing evidence is that the kidney possesses a true 

 portal circulation; and that the use of the terms renal -portal circu- 

 lation, and renal-portal vein is fully justified. 



Finally I wish to thank Professor J. P. Hill for reading through 

 tae manuscript and offering several suggestions; and Mr. G. C. Ma- 

 THisON for his assistance in the literature of this subject. 



Appendix. 



After the manuscript for the foregoing notes was in the hands 

 of the printer another frog with an abnormality of the venous system 

 was found during class-work dissection in the laboratory of this col- 

 lege. Again it was a typical adult male frog (Rana temporaria) and 

 the arrangement of the circulatory system was normal except where 

 the contrary is pointed out. 



Specimen D. Rana temporaria d' (Fig. 5). 

 The abnormality in the specimen now under consideration is 

 somewhat similar to that described by Parker (16) and is readily 

 explicable in the light of Hochstetter's account of the development 

 of the venous system (9). It consists in the entire absence of a post- 

 caval vein except in its inter -renal segment, together with the per- 

 sistence, on the right side, of a part of the posterior cardinal vein 

 and so makes the numbers of recorded abnormalities in this respect 

 nine males and one female. This right posterior cardinal does not 



