CHAPTER VI 



BACTERIA IN NATURAL PROCESSES AND 

 INDUSTRIES 



WHEN or how life first began on the globe no one has as yet 

 been able to discover. Nevertheless, it is true that it has existed 

 through countless ages with no apparent decrease of vigor ! The 

 question arises as to what has become of the waste products of 

 life during these millions of years and from what limitless store 

 was the necessary food supply derived. The condition of the 

 world is hardly conceivable if in the past ages the dead bodies of 

 plants and animals had simply accumulated on the surface of the 

 ground. By their very bulk they would have so covered the earth 

 as to afford no room for the further growth of plants or animals. 

 Nor could the soil furnish a food supply large enough for the count- 

 less millions who have inhabited the earth and the probable mil- 

 lions yet to come without being constantly replenished from an 

 inexhaustible store. The task seems tremendous, yet a large and 

 important part of it is performed by bacteria. 



First of all, bacteria act as scavengers in keeping the ground 

 in a proper condition for the growth of plants and animals. When 

 a tree dies and falls to the ground an innumerable host of micro- 

 organisms at once begin their work of transformation ; the wood 

 becomes softened and finally crumbles into a powdery mass 

 which sinks into the soil and disappears from view. The body of 

 a dead animal undergoes a similar change ; the tissues decay rap- 

 idly, and even the bones are eventually disintegrated and sink into 

 the soil, leaving no visible trace. The process of decomposition is 

 fundamentally the same whether the object be the carcass of an 

 animal, an insect, or a tree, provided the necessary conditions for 

 bacterial growth are present. 



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