2)76 Fortieth Annual Meeting 



would be considered wild trout or not I cannot say. I think the short- 

 gilled fish is now in the aquarium if it has not died or been thrown out 

 since I left there. 



Dr. Osburn : I do not know what the experience of the hatchery 

 men is in regard to that, but the conditions are observed here when 

 the fish are very small, before they become active enough to look for 

 their own food. Of course, the condition in that case would not be 

 such as Mr. Clark describes, that is, of the disease coming on after they 

 were planted. It may be a more complicated problem than we think. 

 There may be more than one thing that causes the trouble. 



Mr. Titcomb : There is one place in Vermont where you can inspect 

 7,000 or 8,000 trout this fall, and can continue for about a month. 

 They will all be handled by one of the fish culturists of the Bureau of 

 Fisheries. If you correspond with Mr. Carter, the superintendent, he 

 can have his men see if there are any short gill covers on those fishes. 

 I think I have seen a few there, but it might have happened in the 

 hatcheries before they were put out. 



Dr. Osburn : The only criterion would be to get hold of those which 

 were in wild streams that never had been stocked at all, if it were 

 possible. 



Mr. Titcomb : Almost all the fish in that pond were hatched arti- 

 ficially. They have been handled for ten years, to the number of 

 8,000 to 10,000 every year. They go up one stream, and are stripped 

 there ; and now we must have fish that are almost entirely artificially 

 hatched, and released partly as fry and partly as fingerlings. But very 

 few have the short gill cover. 



Mr. R. E. Follett, Pittsfield, Mass. : Is this due to malformation 

 from overcrowding, to the nibbling of the fish by each other — nibbling 

 fins and gills, or to the presence of bacteria? 



Dr. Osburn : I have not seen any evidence in the gills that would 

 seem to indicate it was due to parasitism at all. I have not gone back 

 far enough in the history of the young to note whether it is produced 

 by nibbling. It would hardly seem probable, because we know that the 

 opercles, gills, etc., can be regenerated normally and do so under experi- 

 mentation. It may be by nibbling the tip of the opercle it gets turned 

 under and does not get pulled out in the proper place again and re- 

 mains that way. I do not know how the thing starts. 



Mr. Follett : I have seen trout two or three years old with short 

 gill cover; and I have caught them two or three years afterward and 

 the gills were still exposed, although they were in a healthier condition 

 than when liberated. 



Dr. Osburn : They certainly live well here in the aquarium. 



