The Fungus of Salmon Disease. 75 



employ meal worms, as they are easily obtained, but it is often 

 difficult to cause the fungus growth to start on them. If, how- 

 ever, after killing them they be punctured with a needle, a 

 ready growth starts from every point where the needle entered. 



I regret that I have not had opportunity of examining many 

 diseased fish, but on the few I have seen the epidermis was 

 much injured — in some cases, indeed, the true derma under- 

 neath also ; and I am informed that the disease ,only attacks 

 fresh fish in summer on the spots of such injury, but am 

 not anxious to lay weight on second-hand evidence, how- 

 ever honestly given, as a scratch would not be easy to discern 

 with the developed fungus upon it, and diseased fish are liable, 

 by rubbing themselves against stones, to cause such injury at 

 these particular places. 



Last March I was witness to the killing of a fine spring fish 

 of 17 lbs. weight. At the time the river was quite low, and its 

 temperature about 46 Fahr., and no instance of salmon disease 

 had been observed in the river for fully six months. While 

 examining the fish as it lay on the grass I noticed a slight 

 scratch on its head. Although the scratch was in itself insig- 

 nificant, I thought I could discern a fungoid development in it, 

 and called attention to it, but the angler and his gillie were 

 quite unwilling to allow that it could be fungus. Such scratches, 

 I was told, were quite common when the river was low, and 

 always healed quickly, and the gillie protested that a fish would 

 not rise to a fly if the smallest speck of disease existed on it. 

 Not being satisfied myself, I took out my knife and extracted 

 what, I felt convinced, was a particle of growing fungus ; but, 

 to make matters more certain, I removed the remainder (only a 

 speck in all), and placing it in wet cigarette-paper, put it care- 

 fully away in my tobacco-box, and on my arrival home I was 

 fully able to confirm my opinion after a microscopical examina- 

 tion ; and starting some culture experiments from it, I obtained 

 ready growth and a fine crop of true fungus in a short time. 

 The importance of this observation lies in the fact that the 

 disease did not break out in the river with its usual virulence 



