110 Thirh/-Firsf Annual Meeting 



use this large pond will lose such efficae_y as it possesses. This is 

 a matter for experience to settle. Some of the old ponds at 

 Xorthville will prohahly be replaced by excavating a large basin 

 whieli shall be fed with cold spring water and contain natural 

 vegetation. It Avill be stocked with brook trout and the round of 

 fish cultural operations which involves the use of ponds will be 

 conducted in it. It is expected to reduce materially the losses 

 from disease, but whether as a permanent system it will give 

 satisfactory returns remains to be seen. 



The question of the value of cement ponds as a construction 

 for small ponds in general, aside from any question of disease, 

 will I hope be tried out by the experience of the fish culturist. I 

 think they have made a favorable impression at the outset and 

 possibly continued use may show that their greater dural)ility, 

 cleanliness, and sightliness, will more than compensate their 

 greater initial cost. 



DISCUSS [ON OF ]S[R. MARSH's PAPER. 



Dr. Birge : I sliould be glad if Prof. Marsh would say a 

 little as to the nature of the organism he describes, as to whether 

 it is a baccillus or a coccus. 



Mr. Marsh : It appears as every form that a bacterium takes, 

 and when one sees it under the microscope in the tissues it is 

 plainly a bacillus : l)ut when you isolate it on solid media outside 

 of the fish it is ])lainly a coccus, and yet it is the same thing. 



Dr. Birge: How is it in liquid media? 



]\Ir. Marsh : It is intermediate, a sliort rod. 



(^ Does it form spores ? 



A. No, it does not. 



Q. Have you succeeded at all in finding it in the water? 



A. That is what I have been attempting to learn during my 

 last trip to Northville. I have been there about a week, but have 

 not got it yet. 



(^ Does it form a cliaracteristic growth on plates? 



A. Yes, it does. Tlic colony resembles a number of other 

 water organisms ami is not so strongly characterized that you 

 can readily tell it from these. 



Q. Does it liquify ? 



A. It liquifies rapidl}^ 



