260 BOARD OF AGRICULTURE. [Jan., 



crowd out many other things. So that we might be sure 

 that at some time during the fifty years the ground would be 

 covered with grass. At some time the grass would get the 

 best of other things and cover the ground. So also with 

 these bacteria in milk. We have found in our work thus 

 far that we can depend upon certain kinds of bacteria at some 

 stage in the battle getting the best of it. For instance, the 

 lactic bacteria at a certain stage get the better of the others, 

 and that is the reason that the milk sours. Most of the bac- 

 teria in milk will not sour it. If we take those three thousand 

 bacteria that we found in that sample of milk at the start, 

 and the great majority, probably eighty or ninety per cent, 

 of them, would not sour the milk at all. It is only a very 

 few of them that have that power. This small number we 

 call lactic bacteria, and they are like the grass in our ten- 

 acre lot. They get hold in some way, and little by little 

 crowd the others back, and get ahead of them, and very soon 

 the milk sours. Usually by the time the milk is forty-eight 

 hours old these are in abundance. That is one of the results 

 of this struggle for existence by the bacteria of milk, and an 

 almost universal result. Are these results of any practical 

 value? I do not know yet as to this particular result, but 

 that the problem of bacteria in milk is one of immense prac- 

 tical value to dairying I do know. Why? Because your 

 method of handling your milk, your method of handling your 

 butter, and your method of making your cheese are all de- 

 pendent upon the proper handling of these little micro- 

 organisms. And I know another thing: I know that this 

 general problem is of immense importance to the public 

 health. Whereas, many of these bacteria are harmless, and 

 many of them are distinctly beneficial, and probably beneficial 

 even to health, yet some of them are injurious. There is no 

 dairyman, I suppose, in Connecticut who knows anything of 

 modern dairying that does not know that the problem of dairy 

 bacteria in milk is the problem that the health boards of our 

 big cities are working over, and which they are trying to solve 

 in one way or another. So that upon the solution of the 

 problem presented by this struggle for existence going on 

 among the bacteria in milk for the first twenty-four hours is 

 dependent much that is fraught with the greatest significance 

 both to the dairy business and to the public health. Whether 



