v'Vi,^ 



BACTERIAL DISEASES 

 OF PLANTS 



PART I 



A CONSPECTUS OF BACTERIAL DISEASES OF 

 PLANTS 



All our knowledge of these diseases has come within a gen- 

 eration. It began forty years ago with the announcement 

 of the bacterial origin of pear blight by Professor T. J. Bur- 

 rill of the University of Illinois (See Frontispiece), who has but 

 recently passed away.^ During the first half of this period 

 progress was very slow and doubt universal, especially in Europe. 

 In the early study of these diseases a few men were far in advance 

 of their generation, as always happens when a new science un- 

 folds. Photographs of the leading workers of that period, all 

 of whom are still living, are shown in Fig. 1. All were made at 

 that time with exception of Savastano's which reached me too 

 late and is shown separately as Fig. 308. 



It is now twenty-four years since I ventured the statement, ^ 

 that "there are in all probability as many bacterial diseases 

 of plants as of animals." This statement was received with 

 much skepticism, not to mention active opposition, but time 

 has more than borne out my statement, and there is now no 

 one left to dispute it. To-day I will venture another and 

 broader generalization, to wit: It appears likely that event- 

 ually bacterial diseases will be found in every family of plants, 

 from lowest to highest. This prediction is based on the fact 

 that although the field is still a very new one, with no workers 

 in most parts of the world, such diseases have been reported 



1 Born in Massachusetts, April 25, 1839; deceased in Illinois, April 14, 1916. 



2 Am. Nat., vol. 30, p. 627. 1896. 



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