THE FROG ; VISCERA AND VASCULAR SYSTEM 63 



of the mouth, there to be oxygenated again. The blood 

 from the skin and mouth mingles on its way back to the 

 heart with the venous blood, but that from the lungs returns 



Fig. 33. — The urinary and generative organs of a male frog. 



a.ab.v., Anterior abdominal vein, cut short and turned back; bl. y urinary 

 bladder; cl., cloaca; d.ae?., dorsal aorta : f.b. , base of fat body ; f.b-v., 

 vein of fat body ; f.z>., femoral vein ; it. a,, iliac artery; i.v.c, inferior 

 vena cava; k., kidney; k.d., kidney duct ; mso., mesorcbium ; ces. y ceso- 

 phagus ; pl.v., pelvic vein; r.p.v., renal portal vein; r.z>., renal veins; 

 sc.v., sciatic vein ; sr.b., adrenal body ; t.v., spermatic vein ; v.cff., vasa 

 efferentia; ves.sem., vesicula seminalis. The testes are not labelled, nor 

 are the sciatic plexuses, a portion of which may be seen beside the iliac 

 arteries. 



A diagram of these organs will be found on p. 558. 



