MICRO-ORGANISMS 



as to say that it makes but little difference 

 what the soil is, for bacteria of the proper 

 sort will make it fertile, and that the fu- 

 ture of agriculture will be bound up in the / 

 application of the science of bacteriology. ' 

 This science is yet in its infancy, and it is 

 now difficult to gauge the extent of its 

 possible advantageous developments. But 

 already we know that trees need bacteria 

 to prepare their food for them, and that 

 America will be as treeless as Greece and 

 Palestine now are, if we do not put a stop 

 to the washing away of the bacteria-laden 

 soil by the wholesale cutting off of our 

 forests. 



The Protozoa are, if anything, of more 

 ancient and unvarying lineage than the 

 bacteria. So far as we are concerned, 

 those of them which cause disease are more 

 to be dreaded than disease-producing bac- 

 teria. Their chief mode of entrance into 

 the bodies of animals is by the bites of in- 

 77 



