xm 



PHYLUM CHORDATA 



273 



Tlie blood is collected from the kidneys by the renal veins (rn.), 

 which unite to form the large unpaired postcaval vein (pt. cv.). 

 This passes forwards through a notch in the liver, receives the 

 hepatic veins (h.p.) from that organ, and finally opens into the sinus 

 venosus. Thus the blood from the hind-limbs has to pass through 



pr.cv 

 eaelju \ 



l.ctu raif\ \\ 



/ 



^ 



pv 



Fio. 944. Rana texnporaria. The venous system with the heart, lungs, liver, kidneys, and 

 right testis, from the dorsal aspect, abd. abdominal vein ; br. brachial vein ; cd. cardiac 

 vein ; ds. Imb. dorso-lumbar vein ; rf. duodenal vein ; ext. ju. external jugular vein ; fm. 



femoral vein ; gs. gastric vein ; hp. hepatic vein ; hp. pt. hepatic portal vein ; int. intesti 

 veins ; int. ju. internal jugular vein ; kd. kidney ; /. au. left auricle ; Ing. lung ; Ivr. liv 



intestinal 



er; 



ves. vesical veins. 



one of the two portal systems on its way back to the heart : part 

 of it goes by the renal portal veins to the kidneys, and thence by 

 the renal veins to the postcaval, part by the pelvic and abdominal 



