PISCES. 



361 



c.v.L 



FIG. 178. Diagram of the principal vessels in the circulation of a fish, ventral 

 view, a, aorta; au., auricle; br.a., afferent branchial arteries; br.e., efferent branchial 

 arteries; bu., bulbus (or conus) arteriosus; c, carotid; c.a., caudal artery; c.i'.r., right 

 cardinal vein; c.i'.l., left cardinal vein; d.a., dorsal artery; d.c., ductus Cuvieri; g, 

 gills; h.r., hepatic vein; h.p., hepatic portal vein; i, intestine; ;', 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 re- 

 moved from the circulation? 



