998 The American Naturalist. [December, ES 
bodies of animals and plants, and thus enabling the same 
material to be used over and over again for the support of life, 
and hence making possible a constant, perpetual condition of 
nature; and when we remember, lastly, that it is only through 
their agency that plants were originally enabled to get hold 
of nitrogen at all and that it is only through the agency of these 
bacteria that we may hope for a continuance of a supply of. 
nitrogen to the soil, when we remember all these things I 
think we will recognize that the power of the bacteria for 
good far outweighs their power for evil. Without them we 
should not have our epidemics, but without them we should 
not exist. Without them it might be that some individuals 
would live a little longer, if we could live at all. It is true 
that bacteria, by the production of diseases once in a while, 
cause the premature death of an individual; once in a while 
they will sweep off a hundred or a thousand individuals, but 
it is equally true that if it were not for them plant life and 
animal life would be absolutely impossible on the face of the 
world.—Connecticut Agric. Report, 1892. 
