139 



The post-caval vein is entirely absent save in its inter-renal por- 

 tion and is functionally replaced by the persistent left posterior car- 

 •dinal vein which is only present in front of tiie left kidney. 



The posterior cardinal runs forwards from the inter-renal vein 

 j)arallel to the left arch of the dorsal aorta bends round ventrally 

 and mesially to take part in the formation of the left pre-caval vein. 

 It is not dilated at its anterior end and the internal jugular and 

 sub-scapular veins open separately into it. 



The constitution of the renal portal veins is quite normal and the 

 Jeft one runs alongside the left kidney, receiving the dorso-iumbar 



Fig. 2. Fig. 3. 



Fig. 2. Diagram of Venous System of Specimen C. D. A. Dorsal aorta. 

 D. L. Dorso-lumbar. L. P. Left Posterior Cardinal. B. A. Right pre-caval (an- 

 terior vena cava). *S'. V. Sinus venosus. V. Vesicular. Other letters as in fig. 1. 



Fig. 3. Diagram of Venous System of Specimen D. J. V. Continuation of 

 left renal portal {L. R. P.) i. e. Jacobsons Vein. 



in the normal manner. The distribution of the right renal portal 

 vein however is abnormal and is apparently unique although some- 

 what like that, recorded by Shore (9) and Hill (1). This vessel 

 runs up to the lateral wall of the kidney like its fellow on the other 

 side and receives a well marked dorso-lumbar factor. Shortly after 

 this point it leaves the lateral wall of the kidney and passing over 



