I2O SOILS 



nance for the carbon compounds that give heat and 

 energy, so do bacteria look to some similar substance in 

 the soil for their supply. These little creatures are unable, 

 of course, to take their supply in just the way that the 



TWO KINDS OF BACTERIA FOUND IN DECAYING VEGETABLE MATTER 

 (after Pfeiffer) 



higher forms do: they have a way of their own. And 

 why not? They pull compounds to pieces, they seize 

 the carbohydrate therein held, and on it feed that their 

 needs may be supplied. Naturally, then, when bacteria 

 feed, they destroy organic matter. Organic compounds, 

 since they are dead, no longer are able to resent and resist 

 these attacks, consequently fall apart and sink into lower 

 forms, at last to be destroyed entirely as a component 

 structure. It is just the old story in reality : dust to dust 

 and ashes to ashes. The plant dies, the animal dies or- 

 ganic forms disappear and become mingled with the dust 

 of the fields; and this becomes rich and fertile because 

 of the dead therein enclosed : because bacteria have done 

 their work well. 



