22 American Fisheries Society 



food so infected is justly viewed with suspicion, and 

 health authorities are remiss if they allow such condi- 

 tions to exist. 



It cannot be emphasized too strongly that insect larvae 

 in meat, or putrefactive changes have nothing in common 

 with cases of animal parasitism. The helminth parasite, 

 in the alimentary canal particularly, or in the tissues of 

 its host, in somewhat less degree, requires that the 

 animal which harbors it be living. They do not, as a 

 rule, long survive the death of the host. Living nema- 

 todes on the viscera of a butterfish in the market, there- 

 fore, are no indication that the flesh of the butterfish is 

 not perfectly fresh and wholesome. 



Cestodes. — I do not recall any cases of cestode parasites 

 of fishes in this country which, like Bothriocephalus 

 latus, found larval in certain European fishes, develop in 

 man.* If such exist the habit of eating only cooked fish 

 which prevails here precludes any possibility of man's 

 becoming the final host. With the exception of the but- 

 terfish, the marine food fish that I have examined are 

 prevailingly free from cysts in the flesh. In the butter- 

 fish a small cyst, about one millimeter in diameter is 

 found. If the back-bone of a fish which has these cysts 

 in the flesh be removed it will carry away with it prac- 

 tically all of the cysts, which, save in an occasional highly 

 infected individual, are limited to the immediate vicinity 

 of the back-bone, where they are, for the most part, 

 lodged in the spaces between the vertebral spines above 

 and below. On account of their small size and resem- 

 blance to small fish roe there is nothing unpleasant in 

 the sight of these cysts, if they would be distinguished 

 at all, an exceedingly unlikely event. As stated above 

 there is no reason to think that these cysts can develop 

 in man, or indeed in any warm-blooded animal. The 

 New York health authorities are right in making no 

 objection to the use of butterfish as food on account of 

 cestode cysts in the flesh. 



f It has been brought to my attention since this paper was written that 

 Bothriocephaluslatus has recently made its appearance in Wisconsin, 

 where it has evidently been introduced from Norway. 



