28 



ANIMAL BIOLOGY. 



[Part I. 



air. 



two veins (renal portal, r. p.), 1 which will be seen passing to the 

 outer faces of the kidneys, in which case it breaks up into capil- 

 lary plexuses in these organs. 

 From these organs it passes by 

 means of small vessels into a large 

 vein which lies between the kid- 

 neys (post-caval, 10 and 11, pt. 

 c.), 1 and runs up through the base 

 of the liver to the sinus venosus. 

 The blood from the stomach and 

 intestines collects into a large 

 vein (the portal, 10, por.), which 

 carries the blood to the liver. 1 

 There it breaks up into a capillary 

 . v. plexus. From the liver, the blood 

 delivered to that organ by the 

 anterior abdominal, and portal 

 veins, and by the hepatic artery (a 

 branch of the cceliaco-mesenteric), 

 is conveyed into the post-caval by the hepatic veins (10, he). 



As it passes through the capillaries of the various organs of 

 the body, the watery fluid of the blood oozes out and forms the 

 lymph, which collects in irregular cavities called lymph spaces. 

 It is pumped back into the blood-stream by four lymph-hearts 

 (see p. 195). 



4. The Urino-genital System. The urinary organs are the 

 kidneys (8, ren.), elongated red organs lying in the subvertebral 

 lymph space ; attached and closely applied to them are the 

 yellowish adrenal bodies. From the outer edges of the posterior 

 ends of the kidneys arise their ducts (ureters, 8, ur.), which open 

 into the cloaca by minute apertures in its dorsal wall. The 

 ureters of the male have connected with them glandular bodies, 

 the vesiculce seminales. In the ventral wall of the cloaca is a 



a V. 



FIG. 11. RENAL PORTAL AND PELVIC 

 VESSELS : FROG. 



1 When the portal vein has been made out, the stomach, intestines, and liver 

 should be carefully removed, and the subvertebral lymph space opened out 

 without injury to the kidneys, testes, etc. The dorsal aorta, post-caval, and 

 renal portal will then be readily made out, as shown in Fig. 11. 



