THE MILLARDETIAN PERIOD 61 



Bureau of Plant Industry of the U. S. Department of 

 Agriculture. At present nearly every experiment station 

 in the United States has a man or a number of men de- 

 voting a part or all of their time to plant disease investi- 

 gation (Galloway, 1900 : 194-197). 



Discovery of the Bacterial Etiology of Certain Plant 

 Diseases.— During the years from 1878 to 1884 Burrill, 

 in Illinois, working on the well-known fire -blight of 

 apples and pears, discovered that it was caused by bac- 

 teria.' Wakker, a young Dutch pathologist, working 

 on the so-called yellow disease of hyacinths, proved it to 

 be caused by bacteria. He published his results from 

 1883-89.2 These studies were the beginning of a series 

 of most remarkable discoveries of bacterial diseases in 

 plants. Particularly numerous have been these dis- 

 coveries in America, where this class of plant diseases 

 has been brought to the fore through the remarkable 

 investigations of Dr. Erwin F. Smith, who took up this 

 line of work in 1893, publishing his first observations 

 (on wilt of cucurbits) in that year.^ 



The first of these events forecasted the general char- 

 acter of the work and investigations of the Millardetian 



' For a complete list of Burrill's publications on blight during this 

 period, see bibliography in New York (Cornell) Agr. Exp. Sta. Bui. 

 329 : 369, 1913. 



2 Smith, E. F. : The bacterial diseases of plants; a critical review of the 

 present state of our knowledge, Amer. Nat., 30 : 797-804, 912-924, 

 1896. Uncompleted. (Gives an extended abstract of Dr. Wakker's 

 papers.) 



'Smith, E.F.: Two new and destructive diseases of cucurbits: 1. 

 The muskmelon Alternaria. 2. A bacterial disease of cucumbers, 

 cantaloupes, and squashes, Proc. Amer. Ass. Adv. Sci. for 1893, 42 : 259, 

 1894. Abstract Hot. Gaz., 18 : 339, 1893. For further contributions on 

 cucumber wilt, see Bacteria in relation to plant diseases, 2 : 299, 1911. 



