20 BACTERIA IN REI/ATION TO PLANT DISEASES. 



have published. Nearly all of them have grossly neglected the experimental method. 

 Under special diseases I shall have something to say about particular misconceptions, 

 but, I have not felt called upon to point out all the errors strewn over the pages of these 

 handbooks. Their name is legion and some of them have done service for a generation, 

 having been handed down from one author to another, e. g., the " hyphomycete " that is 

 almost always present in the yellow disease of the hyacinth. 



After a consideration of the treatment accorded to bacterial diseases of plants in these 

 handbooks, the reader is well prepared to accept Migula's statement that: "Dieses Gebiet 

 der Bakteriologie gegenwartig zu den verworrensten und wissenschaftlich am wenigsten 

 durchgearbeiteten gehort " (System Bd. I, p. 312). 



In reality, however, the subject is not extraordinarily difficult, if it is approached by 

 the experimental method, not more difficult than new researches in any other branch of 

 science — to cut underbrush and break ground in any field of science is laborious work. 

 This stage is now largely passed and there is considerable definite information on the 

 subject as will appear from what follows. 



