141 



and although it receives a dorso-lumbar factor it gives off no venae 

 renales advehentes to that organ. It is continued, without diminishing 

 in calibre, as the left posterior cardinal vein. 



The left kidney therefore posseses no renal portal supply and it 

 is found also that its volume is .considerably less than that of the 

 right kidney. 



The hepatic veins open separately into the sinus venosus. 



It is interesting to note that the only other example of a female 

 frog in the which the persistence of a posterior cardinal vein has 

 been recorded is the one described by Howes in 1888 (3). In this 

 case however the post-caval vein was also present and as far as I 

 can ascertain this condition has not been described elsewhere for 

 either a male or female frog. If for some reason or other the inter- 

 mediate part of the post-caval vein fails to develope it is easily seen 

 that it is necessary for one or other of the posterior cardinal veins 

 to persist, as in the four cases described above, or for a new venous 

 channel to be developed in order to return the blood from the poste- 

 rior parts of the animal to the heart. The above case of Howes' 

 does not permit of this explanation however and is somewhat diffi- 

 cult to understand. 



Literature. 



1) Hill, J. P., Note on an abnormal connection of the Eenal Portals in a 

 young male frog (Limnodynastes peronii). Proc. Linn. Soc. New South 

 Wales, Vol. 8, 1893. 



2) HocHSTETTER, F., Beiträge zur vergleichenden Anatomie und Entwicklungs- 

 geschichte des Venensystems der Amphibien und Fische. Morphol. Jahrb., 

 Bd. 13, 1888. 



8) Howes, G. B., Note on the Azygos Veins in the Anurous Amphibia. 

 Proc. Zool. Soc, Part 56, 1888. 



4) Joseph, H., Über zwei Abnormitäten im Venensystem von Salamandra 

 muculosa Laur. Anat. Anz., Bd. 20, 1901. 



5) Kerb, J. Graham, Note on the Posterior Vena Cava in Polypterus. Proc. 

 Roy. Physiol. Soc. Edinburgh, vol. 18, 1910. 



6) Lyle, H. W., Abnormal conditions of the circulatory system of the frog. 

 Proc. Physiol. Soc. Journ. Physiol., Vol. 24, 1899. 



7) O'DoNOGHUE, C. H., The Persistence of Posterior Cardinal Vein in the 

 Frog together with Some Remarks on the Significance of the Renal Por- 

 tal System. Anat. Anz., Bd. 36, 1910. 



8) O'DoNOGHUE, C. H., Tho cases of abnormal hearts and one of an abormal 

 Anterior Abdominal Vein in the Frog. Zool. Anz., Bd. 37, 1911. 



9) Parker, W. N., On the occasional Persistence of the Left Posterior Car- 

 dinal Vein in the Frog with Remarks on the Homologies of the Veins 

 in Dipnoi. Proc. Zool. Soc, 1889. 



