90 American Fisheries Society 



co-operate in any way, except to grudgingly supply a few fish and 

 spawn. The first bunch of fish we hatched were steel-head trout. 

 As we had no facilities at the Laboratory, I hatched them at the 

 State University at Grand Forks and transported them to the 

 lake when they were ready to plant. We also had some wall-eyed 

 pike. The work that summer was rather discouraging. 



The next summer things were in better shape at the laboratory, 

 and it was then that Dr. Brannon made a discovery which has 

 proved to be the solution of our difficulty. He was working on the 

 plants of the lake and found that those living in the alkali water 

 showed a pressure five times as great as those living in fresh 

 water. Immediately we planned out a new line of work, applying 

 the same principle made use of to accommodate a man to work 

 under high air pressure, that is, the man goes from one chamber to 

 another with increasing pressure until finally he is able to work in a 

 pressure that would kill him in five minutes if he went there 

 directly. When he is done with his shift he goes back gradually 

 and is none the worse for it. 



We constructed a series of cement tanks for experimentation 

 and in six weeks had worked out the problem with great success. 

 The fish are put into fresh water for a day and then twenty per 

 cent of the alkali water is added. The next day the percentage of 

 alkali water is raised to forty and the next day to eighty. Then 

 they go into the full strength alkali water for a day, after which 

 they are ready to go into the Lake, with a loss of only about one- 

 tenth of one per cent. We have tried black bass, steel-head and 

 rainbow trout, wall-eyed pike, bull-head and pickerel (though the 

 pickerel are not to be introduced into the lake). We hope to have 

 the plant enlarged, as the one in use was built merely for 

 experimental purposes. 



We have also tried the experiment of hatching eggs in the 

 alkali water. We received the eggs from Put-in-Bay, Ohio, and so 

 put them all in fresh water, except one jar which was supplied with 

 the lake water. The fish hatched in the alkali water are better 

 and stronger and in the five years that we have used the pure lake 

 water we have failed to find the least trace of fungus. You all 

 know how interesting it is to work with fungused wall-eyed pike 

 eggs, but we have seen no trace in the alkali water. 



