358 



The right kidney is again larger than the left, and there is asym- 

 metry in the constitution of the inter-renal, for, although it runs 



medially between the 

 kidneys to their ante- 

 rior end, it received 

 larger tributaries from 

 the right than from 

 the left. 



Specimen C. 

 (jRana temporaria 

 (Fig. 3). 

 This specimen is 

 unique in the possession 

 of two persistent poste- 

 rior cardinal veins, and 

 in addition has no ante- 

 rior part to the post- 

 caval. The posterior 

 part of the post-caval, 

 persisting as an inter- 

 renal, is a fairly sym- 

 metrical vein dividing 

 at the anterior end of 

 the kidneys into two 

 branches , one going 

 to each persistent post- 

 cardinal. 



The two cardinals 

 are of very unequal 

 size, that on the 

 right being much the 

 larger, suggesting that 

 practically the whole 

 of the blood normally 



Fig. 3. Diagram of Venous System of Specimen C. 

 L.Ä. Left Anterior Vena Cava, L.R.P. Left Renal Portal, 

 B.P. Right Posterior Cardinal. Other letters as before. 



A. Dorsal surface of both kidneys to show the 

 distribution of the renal portal veins. 



Rana. In Rana the cutaneous is far larger than the muscular, while in 

 Limnodynastes the muscular is the large main trunk and the cutaneous 

 only a small tributary. With the decrease in the relative size ol the 

 cutaneous factor is correlated an increase in the size of the deflated 

 lungs which were larger in the Australian than in the English trog, 

 although the former was only two-thirds the size of latter. This is 



