HOUSEHOLD BACTERIOLOGY 



Bacteria as 

 Scavengers 



Fig. 28. Bacteria 

 which Help IE 

 Plant Food. 



in Soil 

 Making 



As soon as an organism begins to live it begins to 

 die ; that is, certain cells or parts of cells die and are 

 perhaps cast off from the rest that the whole may 

 not be injured. Animals and 

 plants die and become dan- 

 gerous to the welfare of 

 other animal life, especial- 

 ly to man. The wastes of 

 life, of his own life even, are 

 man's greatest menace. 

 Here come to his aid these microscopic scavengers, 

 the bacteria. No doubt the molds assist in the process 

 but the balance of the work is done by the bacteria pres- 

 ent in such infinite numbers everywhere on the earth 

 where organic matter exists. 

 Through their agency all 

 dead animal and vegetable 

 substances that is, all or- 

 ganic matter are changed in- 

 to inorganic matter, into the 

 chemical compounds or ele- 

 ments out of which they were 

 originally constructed, and 

 which are harmless or helpful 

 to the life of the world. 



A tree falls in the woods; an elephant or a bird 

 dies in the jungle ; just then and there the millions of 

 bacteria in the soil and the air are ready to seize upon 

 the dead bodies, and in time all the animal and vege- 



Fig. 29. Bacteria Found in 

 Soil and on the Roots of 

 Clover, Peas and Other 

 Leguminous Plants. 



