136 



Bacteria in Relation to Country Life 



forming and non-spore-forming organisms, and aerobic 

 and anaerobic bacteria. 



But whatever interest is attached to the size and 

 shape of the soil bacteria as viewed under the micro- 



Fig. 18. Colonies of soil bacteria. 



scope, it must be remembered that there is reserved 

 for them a certain task, upon the proper performance 

 of which depends the well-being of more highly organized 

 creatures. They are the connecting link between the 



