138 



the iüuoniinate vein approximately opposite to one anotlier as is 



usually the case, they are fairly widely separated and the external 



jugular joins the innominate much nearer the heart than does the 



sub-cl avian. 



The hepatic veins open directly ioto the sinus venosus and so the 



whole of the post-caval vein is missing save in its inter-renal portion. 

 All the other viscera and vessels were normal. The kidneys are 



equally developed, the renal portal supply is quite normally constituted 



and each renal portal vein enters the 

 corresponding kidney by means and 

 venae renales advehentes in the usual 

 manner without a direct connection 

 with the inter-renal vein. 



Specimen B. 6 Rana temporaria. 

 This was an adult male Rana tem- 

 poraria and apparently normal in other 

 respects. The abnormality is very 

 similar to that described above. It con- 

 sists in the entire absence of the post- 

 caval vein except in its inter-renal 

 portion and in the persistence of a 

 right posterior cardinal vein anterior 

 to the right kindney. The posterior 

 cardinal has no direct connection with 

 the kidney but is continuous with the 

 inter-renal vein. The persistent car- 

 dinal vein differs from that in the 

 preceding specimen at its anterior end 

 as it is not dilated and the internal 

 jugular and sub-scapular veins open 

 separately into it. 



The renal portal system is nor- 

 mally constituted and the kidneys 

 equal in size. It is unnecessary to 

 figure this example as it is so similar 

 to the preceding one. 



Specimen C. S Rana temporaria 

 (Fig. 2). 

 This is a small but quite adult male Rana temporaria and is, as 



far as can be seen, normal in other respects. 



Fig. 1. Diagram of Venous System 

 of Specimen A. A. A. Anterior ab- 

 dominal. B. Brachial. E. J. Exter- 

 nal jugular. F. Femoral. I. Inno- 

 minate. /. J. Internal jugular. I. R. 

 Inter-renal. L. A. Left pre-caval 

 (anterior vena cava). L. B. P. Left 

 renal poital. Jlf.CMusculo-cutaneous. 

 P. Pelvic. li. P. Right Posterior Car- 

 dinal. R. B. P. Right renal portal. 

 S. Sciatic. S. C. Sub-clavian. S.S. 

 Sub-scapular. Sp. Spermatic. 



