1899.] PUBLIC DOCUMENT — No. 33. 145 



a view to their repression. In regard to the industrial side 

 of botany, it should not bo forgotten that it owes a great 

 deal to the patient investigations of the many scientific 

 workers of the past, who have devoted their attention to 

 matters of purely scientific interest; and our stations would 

 not be where they are to-day were it not for the labors of 

 these men. 



In connection with the characteristic utilitarian features 

 of the present American botanists, it may be of some inter- 

 est to observe the differences existing between European 

 and American methods of combating pests. Some of the 

 most effective spraying solutions were discovered in Europe, 

 but ; the methods of applying them and the results obtained 

 by their use to our crops far exceed anything ever accom- 

 plished there. To one who has paid any attention to the 

 manner of growing plants in Europe and the methods which 

 are pursued in the control of plant diseases, it would seem 

 no exaggeration to state that more is accomplished in this 

 direction in the United States in one year than in Europe in 

 five years. 



The past season has been what might be termed a normal 

 one, although, as in every season, some fungi were espe- 

 cially predominant. There are, however, every year types 

 of fungous diseases which affect our shade trees. 



Pathogenic Fungi. 



The fungous diseases which have been specially common 

 upon our shade trees this last season are as follows : — 



I Huclc Spot of the Maple (Rhytisma acerinum, (.P), Fr.). 



This fungus is characterized by elevated black spots or 

 blotches upon the surface of the leaf, and, while it is not un- 

 common to a few maples, it has been especially abundant on 

 the silver maple. 



