FUNGOUS DISEASES 9 



the winter. Hence, these latter are called the winter 

 spores. 



It is evident from the above account of this 

 fungus parasite, that remedial or preventive meas- 

 ures are useless after the enemy has become estab- 

 lished within the tissues of the plant. But its ingress 



Fruiting Branches 



Greatly magnified 



may be prevented by coating the green parts of the 

 vine with some substance having a destructive effect 

 upon fungus spores. The salts of copper have such 

 an effect, and in consequence have come into general 

 use as fungicides. 



From the foregoing illustrations the reader will 

 have learned that spraying is simply an easy and prac- 

 tical method of distributing certain substances having 



