Moore. — Nezv Species of Parasite in Trout. 83 



Because of these differences the species name of salmonis is 

 proposed and our American form designated as Octomitus 

 salmonis. 



Schmidt states that he found the organism (14) widespread 

 among the rainbow and brown trout fingerlings, in the lumen of 

 the intestine and in the gall bladder, yet he failed to observe a 

 pathological condition arising from their presence and concluded 

 that the organism was a harmless commensal. The nature of 

 the disease produced by the American species is different. Our 

 species causes serious lesions in the intestinal epithelium, terminat- 

 ing fatally in many cases. 



The parasites considered above are widely distributed in 

 nature. Giardia is found in man, dogs, cats, rabbits, rats, mice 

 and frogs. No authentic record is as yet at hand of its occur- 

 rence in fish. Hexamitus is common in frogs, toads and other 

 batrachians and has been recorded for turtles and rats. Octomitus 

 is distinctively a parasite of fish, occurring in both marine and 

 fresh water forms. 



REMEDIAL MEASURES. 



With the isolation of the disease organism accomplished and 

 the facts in the life cycle fairly well known, it is possible to 

 consider preventive measures. Complete eradication of the 

 disease can hardly be expected since resistant cysts are certain 

 to be widely disseminated through one agency or another — by 

 flies or other insects and by floating bits of excrement carried 

 off in the current of the water. Nor is it to be expected that a 

 disease of this nature, in which the organism passes a part of its 

 life history within the walls of the intestinal tract of the 

 fish, can be cured by administering drugs. Similar parasites 

 (Giardia, Plate II, 15) in man and in cats have not responded 

 successfully to treatment with carbon tetrachloride, * a chemi- 

 cal used with great success in the eradication of hookworm, nor 

 with other drugs, emetine, B-napthol, etc. (Wenyon, 1915) used 

 also experimentally in infections of Giardiasis. It would seem 

 that hope lies in the adoption of preventive measures which will 

 better control the disease and prevent epidemics. 



Besides the adoption of better and more thorough sanitary 



• From the unpublished researches of M. J. Hogue on the effects of 

 carbon tetrachloride in Infections of Giardia In man and In cats. 



