412 



THE PIGEON. PHYLUM CHORDATA 



of two iliac veins in front of the kidney. Each ihac vein is formed 

 by the union of a femoral, a renal, and a big hypogastric which 

 passes upwards through the kidney. Behind the kidneys the 



Ill 



Fig. 326. — Heart and venous system of pigeon. — From Thomson. 



R.A., Right auricle ; R.V., right ventricle ; L.V., left ventricle ; L.A., left auricle ; P.V., pulmonary veins ; 

 P. A., pulmonary arteries ; /., jugular ; Br., brachial, and P., pectoral joining to form the precaval 

 vein ; H.V., hepatic ; E.P., epigastric ; I.V.C., postcaval vein ; CM., coccygeo-mesenteric ; I.V., iliac ; 

 F., femoral ; R., renal ; Sc, sciatic ; Hyp., hypogastric or ' renal portal ' ; i.il., internal iliac ; C, caudal ; 

 K., kidney. 



hypogastrics arise in the following wa}^ The little caudal vein 

 forks into two branches, each of which runs through one of 

 the kidneys as a hypogastric. Each hypogastric is much larger 

 than the caudal of which it is a branch, because at the bifurcation 

 another vein, the coccygeo-mesenteric from the cloaca and large 



