238 



HITCHCOCK'S ANATOMY 



FlG. 239. 



Circulating Apparatus of the Fish. 



424. Accessory Hearts — Caudal Heart. — Among many 

 fishes are found what are termed Accessory Hearts, or small 

 muscular organs which seem to aid in the propulsion of blood 

 through the different parts of the body. Thus, in the myxine, 

 the portal vein is distended into a large sac, which expands 

 and contracts alternately; and in eels there is found upon 



424. What are the accessory hearts of fishes f 



