Finally, spray in anticipation of disease, and do not 

 delay until too late. If a speck of mildew appears on a 

 leaf it is certain sign that a fungus spore had fallen on 

 the leaf previously, had germinated there and penetrated 

 the tissues. Now if that particular leaf had been 

 sprayed the spore that alighted on its surface would have 

 been killed, and no injury would have followed. There- 

 fore anticipate the advent of mildew which is certain to 

 appear. The vain endeavour to arrest an epidemic is 

 disheartening, the means of checking its appearance are 

 simple and certain. 



Fungi are so very different in their mode of growth 

 from that of any other group of plants that some 

 knowledge of their peculiarities is necessary to prevent 

 loss of time and expenditure of energy in wrong 

 directions in attempting their destruction. 



The majority of parasitic fungi produce two or 

 more totally different kinds of fruit, each of which 

 serves a special purpose. Taking Rose mildew as an 

 example, the familiar whitish patches that appear on 

 young Rose leaves early in the season, consist of 

 mycelium or spawn that bears myriads of exceedingly 

 minute spores. These spores are produced in rapid 

 succession throughout the summer months, and are 

 capable of germinating and infecting a plant the 

 moment they are ripe. Such are called summer spores, 

 and their use to the fungus is to enable it to spread 

 quickly and extend its range of distribution, hence 

 epidemics of disease are invariably due to summer 

 spores, which retain their vitality only for a few days. 



