364 



ZOOLOGY 



c.v.r; 



c.v.l. 



FIG. 181. Diagram of the principal vessels in the circulation of a fish, ventral view, a, 

 orta; OH., auricle; br.a., afferent branchial arteries; br.e., efferent branchial arteries; bit., bulbus 

 (or conus) arteriosus; c, carotid; c.a., caudal artery; c.v.r., right cardinal vein; ../., left cardinal 

 vein; d.a., dorsal artery; d.c., ductus Cuvieri; g, gills; h.v., hepatic vein; h.p., hepatic portal vein; , 

 intestine; j, jugular vein; k, kidney; /, liver; r.p., renal portal vein; s.v., sinus venosus; v, ventricle. 



Questions on the figure. Follow the general course of the circulation, noting 

 changes in the character of the blood in various capillary regions. What is the 

 extent of the hepatic portal system? Of the renal portal? Where is the purest 

 blood in the body? Reason for your answer? What do you mean by "impure" 

 blood? Where are the chief impurities removed from the circulation? 



