ill Tliiriij-First Annual Meeting 



that case one ^A\ infected from the can would infect the entire 

 pond. 



Prof, ^larsh: The can is a possible source of infection. 



Dr. Birge: But not a probable one? 



A. Xo, because the cans are used constantly for that pur- 

 pose without producing infection. 



Q. You had the disease there before the fish were trans- 

 ported ? 



A. Yes, but not in these cement ponds, of course. 



Mr. Clark : There is one point that Prof. Marsh did not 

 bring uj). The fry that died in the troughs last spring wlien he 

 was there were receiving water from the upper spring that had 

 never had a fish in it up to that time — later we put some in it — 

 but up to the time the fry commenced dying in the troughs in 

 the house, the water came from the upper spring, which never, in 

 all of its twenty-six years had had a trout in it. 



The President : What was the percentage for mortality in 

 the trough ? 



Mr. ^larsh: They all died, except sometimes there was a 

 little remainder that we called immune, but a very small per cent 

 of tlie whole — I cannot say just what, l)ut not over from 1 to 5 

 ])cr cent — they practically all died. 



Mr. ( "hirk : There is one point in this matter that l)others 

 mc. Prof. ]\Iarsh has now almost come to the conclusion that 

 til is infection of bacteria is in the water as it comes out of the 

 ground. Xow, if that is a fact why was it ]iot there and why did 

 not this ])eculiar disease aft'ect our trout before a certain time, 

 iiol more than two years ago? Why have we not had some of 

 ii <luriiig ilie whole twenty-four years previous to that time? 

 A\'hen \vi' did have diseased trout (and we had an epidemic once 

 before when Prof. Gurley was there) it was not pronounced to 

 be the same disease. 



Mr. Marsh : I cannot explain why it was there many years 

 ago, but it may be compared to volcanoes which erupt intermit- 

 tently. T think it is just some natural change in the earth below 

 which l)riiigs this organism into the water. It is some change in 

 the constituents of the water — that is the only explanation I can 

 make of the infection starting up as it did. 



T)r. Birge: Is not tluTc another ])()ssil)le explanation of it? 



