PREFACE 



1 



■^HE voluminous literature dealing with injurious bacteria 

 contrasted with the meager volume devoted to a considera- 

 tion of the beneficial class leads many to conclude that most bac- 

 teria are injurious. This is a wrong conclusion, as most mi- 

 croorganisms are beneficial. Moreover, most of the writing on 

 this latter class is technical and accessible only to the college man. 

 Only a small fraction of the individuals of the United States ever 

 reach the college. Yet the workings of the beneficial bacteria 

 are of importance to all. The soil bacteria are of special eco- 

 nomic importance to all tillers of the soil because the productivity 

 of the soil is intimately associated with their activity. True, they 

 toil for the unskilled as well as for the skilled tiller of the soil — 

 but the one trusts to chance, the other to reason. The different 

 results obtained by the two classes of workers are reflected in the 

 harvest. 



This little book is an effort to present in non-technical lan- 

 guage the fascinating story of the class of microorganisms which 

 inhabit the soil. It is hoped that it will prove valuable not only 

 to the high-school student but also to the general reader, and 

 especially to the agriculturist. If to these it furnishes a faint 

 glimpse into this wonderful realm and creates interest for knowl- 

 edge in this vital subject, the authors will feel that their labors 

 have not been in vain. 



It is with the greatest of pleasure that we express our thanks to 

 Professor William Peterson for offering valuable suggestions as 

 well as to Mrs. Blanche C. Pittman for her painstaking care in 

 the preparation of the manuscript for the press. 



J. E. G. 



jl/. v^« vjr. 

 Logan, Utah, 

 April, 1925. 



