58 HISTORY OF PHYTOPATHOLOGY 



Kiihn. The attempt to serve this class of readers is 

 indicated in the title of the books published; (4) the 

 theory of the autogenetic origin of disease was almost 

 completely discredited by the epoch-making discovery 

 and demonstration of the causal nature of entophytic 

 organisms, especially fungi, found associated with dis- 

 ease lesions. This doctrine of pathogene responsibility 

 thus firmly established by the work of Pasteur, de Bary, 

 Kiihn, Hartig, and others was to inspire and shape the 

 remarkable developments of the science during the suc- 

 ceeding period. HaUier sought in his treatment of the 

 subject to counteract this to some extent by emphasizing 

 the influence of soil, climate, and predisposition of the 

 plant. Hauler's doctrine of predisposition ' was to be 

 more ably developed by Sorauer during the next period, 

 as we shall see; (5) control of plant diseases was for the 

 first time placed upon a sound basis, made possible, of 

 course, by the recognition of the true relation of fungi 

 to plant diseases. Kiihn's work on seed disinfection 

 was the great achievement in this direction. 



THE MILLARDETIAN PERIOD 



The Millardetian or economic period extends from 

 1883 to about 1906. This period is characterized by 

 the emphasis that was placed upon the economic 

 features of plant pathology. It was ushered in by a 

 number of remarkable and far-reaching events and dis- 

 coveries. 



Discovery of Bordeaux Mixture.— A French patholo- 

 gist, Millardet, with whose name this period is desig- 

 nated, began his experimental work with bordeaux 



