THE AUTHOR 



was born in 1898; was until recently Assistant 

 Bacteriologist at Rothamsted Experimental 

 Station, Harpenden, England; is Hon. Corres- 

 ponding Editor of Chronica Botanica, the 

 international plant science news magazine; and 

 has written Microbes by the Million, a layman's 

 introduction to the spirit of microbiological and 

 other science. 



PRINTED IN GREAT BRITAIN BY 

 EBENEZER BAYLIS AND SON, LTD., THE 

 TRINITY PRESS, WORCESTER, AND LONDON 



