Anicrioiii Flshnics Society. \\T) 



There are quite a iiuiiiIht of bacteria just on the edge of beino- 

 pathogenic and which are ordinarily not pathogenic. That is 

 true of the colon Ijaeillus. You get a particularly virulent group 

 of them and they will cause disease, while under other conditions 

 they do no harm; and it is perfectly conceivable that you have 

 got a pathogenic form of a l)acillus which is ordinarily not patho- 

 genic; and then it is also possil)le that the resisting power of the 

 fish has been somewhat diminished; so that it may be both of 

 those conditions or either of them in combination which has 

 caused the infection. 



Prof. Marsh: Do I understand you to mean Ibai ibis organ- 

 ism may have been there all the time ? 



Dr. Birge: If it is a water organism I sliould conjeclure 

 that it has been there all the time. 



Prof. Marsh: Yes, but it has changed its habit — that is a 

 very reasonable supposition, but one can never find out about it^ 

 to a certainty. 



Dr. Birge: If you find this organism in the water it may 

 be entirely possible for you to find it in the water of other 

 hatcheries, but not developing in a pathogenic way. 



Prof. Marsh: Y"es. 



Dr. Birge : If you get it in tlie water here I think you ought 

 to look for it where the disease is not known. 



Prof. Marsh: You mean attempt to find a hanidess form of 

 it somewhere else. 



Dr. Birge : Y"es. 



Mr. Lydell: Was there any vegetation in those springs 

 previous to this disease appearing there? 



Mr. Clark: Yes, all of our water tliere will gTow vegetation, 

 principally of a certain kind of moss, but there is not any gi-eat 

 quantity. 



The President: Would it form a scum on tht' top if aUowed 

 to remain ? 



Mr. Clark: Ob. no sir. nothing of that kind — it is a grow- 

 ing vegetation of a limy nature, that is cleaned out from time 

 to time. 



