194 American Fisheries Society 



I attributed this largely to the fact that in placing the young fry in the 

 water of the larger lakes, where there was a superabundance of food, 

 that they gorged themselves to death. This led me to construct at the 

 head of each lake a small nursery, in which there was not any great 

 abundance of food : and I turned the fish into these nurseries and re- 

 tained them until they reached one to three inches in length, and then 

 released them into the larger lakes. This system gave me better re- 

 sults, but I had one lake in particular on which shores were very pre- 

 cipitous, at an angle of 45°, and whilst I had transferred fish 3, 4 and 6 

 inches in length into that lake and they nearly all lived, whenever I 

 transferred fish direct from the hatchery into this lake where these 

 precipitous shores were, they invariably all died. I hardly ever saw 

 one young fish after making this transfer. That was a mystery to me. 

 For a number of years I could not find any solution of it ; and finally 

 it occurred to me that in transferring the fish from these shallow 

 hatching boxes at the hatchery to the deeper water, the increased 

 pressure on the bottom killed them. I recalled the circumstance of fish 

 being brought up from the greater depths of the ocean to the surface 

 for examination, and on reaching the surface they were all invariably 

 dead. Well, now, I thought if that occurred in bringing them from 

 the deep water to shallow water, why should it not occur in taking 

 them from the shallow hatching troughs and transferring them to 

 water which, within a few feet of where they were planted, was 25 

 or 30 feet deep. I thought this must be the cause of this great mor- 

 tality. I studied the matter, and the more I studied the more evidence 

 I could find, but only circumstantial evidence. I communicated with 

 the U. S. Fish Commission at Washington, and they told me my theory 

 was not correct, that the small fish were consumed by the larger fish 

 in the water. But if there were any larger fish in the water at that 

 time they knew more about it than I did. There were none, gentlemen. 

 In transferring small trout fry from the hatching troughs to larger 

 bodies of water there is usually a large percentage of loss. This loss is 

 supposed, by those who do not closely study the conditions, to be due 

 to the cannibalistic habits of larger trout. While cannibalism does 

 prevail to some extent among all members of the trout family, I think 

 they are accused of more in this line than the facts will justify and 

 that the great mortality among newly planted small fry is caused more 

 by unfavorable environment than by cannibalism. If any of you have 

 had a similar experience I would like to hear it and to receive some 

 corroborative evidence as to the correctness of my theory. 



(Mr. Land here exhibited in small bottles preserved specimens of 

 various insect life, which he described.) 



Mr. Land: I just want to draw your attention to the insects that 

 tbe trout live on, and to the fact that the same insect, the caddis fly, 

 in its larval or gnit state, destroys the eggs and the baby trout. I 

 show you here a specimen of a caddis fly. This fly throws a web 

 around so that it can feed on 9 eggs. This was taken off the trays in the 



