96 THE NEW AGRICULTURE. 



matter thus formed and the stench arising from it are the evi- 

 dences to our senses of the slaughter of the battle and the fury 

 of the fray. It is true that the struggle itself goes on beyond 

 the reach of our vision, for the combatants are too small to be 

 seen by the naked eye, but by the aid of the microscope we 

 may see the vast hordes of these tiny creatures conducting 

 themselves with desperate valor, and find many of our little 

 allies dead upon the field where they have fallen, but not be- 

 fore each had embraced at least one of his antagonists with 

 the grip of death. They are never panicstricken, they are 

 never out-generaled ; if they are beaten it is simply because 

 they are overwhelmed. 



It is not only within the living animal body that infinitesimal 

 organisms live and have their being ; they are ubiquitous. The 

 whole vegetable world is alive with them. All organic mat- 

 ter swarms with them. They turn your cider to vinegar, they 

 sour the milk and ripen the cream for the dairyman. They 

 are the active agents in every process of fermentation. All 

 decay and putrefaction are due to them. They gather and fix 

 and feed nitrogen to the vegetation needing it. They evolve 

 acids of various kinds they are manufacturing chemists. 

 There is division of labor among them: they turn out differ- 

 ent substances. They are carriers, bringing food within the 

 appropriating reach of plants ; and the class with which we 

 are at present chiefly concerned serve as an efficient and in- 

 defatigable commissariat for the innumerable armies of grow- 

 ing vegetation which would starve and die but for their cease- 

 less labors. 



As may be imagined, bacteria are of many orders, families 

 and species. If we should compare them with all the visible 

 forms of animal life upon the earth bipeds, quadrupeds and 



