Moore. — New Species of Parasite in Trout. 95 



noticed that some of the badly afflicted fish are quite black— notably the 

 smaller ones. 



Mr. Foster: It is suggested to me that possibly the liver may be re- 

 sponsible. I have been told by authorities on the feed of animals in zoological 

 gardens that the feeding of liver to those animals produced conditions quite 

 similar to those that Dr. Moore has described. 



Ds. Moore: The fact that this disease becomes pronounced when they 

 are about six weeks old, shortly after artificial feeding commences, leads 

 me to suspect that the trouble may be aggravated by the kind of food given, 

 but this is the first season I have had them under observation. We have 

 secured many leads on which to work in following years, and that phase 

 of the problem should certainly be studied. 



Mr. J. W. TiTCOMB, Hartford, Conn.: We apparently had a disease of 

 that description at a rearing plant where we were taking fish from two 

 different hatcheries; and we attributed it to one of those hatcheries. First 

 we thought it might be blamed on the brushes, so we had them sterilized. 

 Whenever we found a fish boring we let it go into the stream below, and 

 although the water was largely from this same rearing plant, the fish 

 seemed to recover. In fact, we had quite a large school both above and 

 below the rearing plant that thrived splendidly in the natural stream. 



Dr. Moore: In a similar situation I found a trout about 714 inches 

 long carrying the organism. The chances are that it had eaten an infected 

 fish that had been discarded. 



Mr. TiTcoMB : Do you think there would be danger of spreading the 

 disease by planting trout from a trough in which the disease you have de- 

 scribed had been discovered? 



Dr. Moore: From the standpoint of our knowledge of hygiene and 

 sanitation, the best plan to follow, it would seem, would be quarantine ; 

 that is quite contrary to our practice. 



Mr. G. C. Leach, Washington, D. C, : Do you think the disease may be 

 attributable to unsanitary conditions in feeding? 



Dr. Moore: Not to unsanitary conditions, because at this hatchery where 

 the epidemic has occurred annually the sanitary conditions are excellent. 



Mr. Leach : You spoke of the appearance of the disease about six 

 weeks after the fish had hatched. I would think it possible that the fish 

 were fed a little too soon, causing a form of indigestion. 



Dr. Moore : That is possible. They were hatched in February and the 

 disease became apparent the first of April. 



Mr. Leach : That would be about right, then ; feeding would be started 

 at about four weeks of age, or possibly a little earlier. At the Manchester, 

 Iowa, station they apparently had that disease three years ago ; and they 

 have been starting their fish on beef heart and later on feeding them sheep 

 liver. I am told that last year they had absolutely no trouble. 



Dr. MoorE: That is quite remarkable; because at one of our hatcheries 

 where they feed along similar lines the disease is present, though not in 

 epidemic form. 



Mr. Leach : I was wondering if the melting snow would have anything 



