20 BACTERIA IN RELATION 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 gehért”’ (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. 
Se nO 
