86 American Fisheries Society. 



what happens in chicks, where it is known that the disease "bacillary 

 white diarrhoea of chicks" is so transmitted, it seems highly probable. 



Mr. Adams : The reason I ask that question is that our brood stock 

 at our fish hatchery at East Sandwich, consisting of about 25,000 fish, 

 was absolutely wiped out three years ago by what our biologists iden- 

 tified as furunculosis. We practically abandoned a portion of the 

 hatchery for a year, and we carried out the sterilizing and prophylac- 

 tic measures which you have described. Despite our efforts we have ' 

 reason to believe that the same disease has appeared at a couple of our 

 rearing stations this year. We know of no way to account for the 

 communication of the disease unless it was through the egg, for no 

 small fish have been sent from this hatchery to the rearing stations. 



Dr. Moore: Do you think that a bird could have been the carrier? 



Mr. Adams: It is barely possible, because we have the usual run- 

 ning fight with the kingfisher and the blackcrowned night-heron, and 

 even with the catbird and the robin. 



Dr. Moore: The question comes to me, because two lakes in the 

 Catskilis quite isolated from each other have been infected. There had 

 never been any contact between the two lakes so far as the transfer of 

 either eggs or fish is concerned. It looks in that case as if a bird might 

 be the transferring medium. 



Mr. Adams: In regard to Octomitus, how long will the shell of the 

 spore remain intact in open water and remain sufficiently vital to ger- 

 minate when, subsequent to its being deposited in a stream, it finds 

 lodgment in the pi'oper chamber of a fish to undergo further develop- 

 ment? 



Dr. Moore: I cannot answer directly from my own experience. 

 Dr. Schmidt, in his work in Bavaria found that the spore was very 

 resistant to drying and to heat. His experiments extended over an 

 interval of several days. It is quite possible that the spore can retain 

 its vitality in water for weeks or even months and resist an equal period 

 or longer of drought. 



Mr. Adams: If this disease is found prevailing in a hatchery, 

 would you advise the liberation of the fish on the theory that upon being 

 restored to the wild state they may cure themselves? 



Dr. Moore: I believe they do not entirely cure themselves. The 

 infecting organism must perpetuate itself and on this account it would 

 be impossible to believe that the fish, when introduced into wild waters, 

 would be rid entirely of the germ. The fish are doubtless much helped 

 by their more extensive range over wild waters and by securing their 

 natural food, and to this extent improvement could be looked for. 

 There is always the possibility however of infection being spread by the 

 carriers. 



Mr. Adams: Would a change in the temperature of the water; that 

 is, a rise in temperature, retard or speed up the disease? 



Dr. Moore: It would tend to speed up the disease judging by the 

 influence of increasing temperature on cultures of the organism. 



