VI PREFACE TO SECOND EDITION. 



edition is a considerable extension of the treatment of bacterial 

 diseases of plants that have received so much investigation in the 

 last ten years. With these additions it is hoped that the present 

 edition will be a fair summary of our present information upon the 

 relation of germ life to agriculture. 



H. W. C. 



MlDDLETOWN, CONN. 



June 1-5, 1909. 



