FUNGI 17 



modes due to human agency already mentioned ; and 

 perhaps the most efficient method of all is that effected 

 by syringing. By this means spores are dispersed over 

 every part of a house, some of which, in the ordinary 

 course of things, will fall upon damp leaves. Syringing is 

 simply tempting Providence in those instances where the 

 house contains plants of one kind only, and where the 

 presence of a disease is known, or even suspected. 



It has been suggested, in the case of the chrysanthemum 

 rust epidemic, that in one instance the disease was in- 

 troduced owing to syringing the plants with rain water, 

 supposed to contain the spores of the fungus that had 

 been carried from the roof into the cistern. 



I am quite conscious of the fact that the practical man 

 will retort, Gardeners must move about among plants, and 

 spraying is a necessity. This may be considered good 

 argument ; nevertheless, it is well to be in possession of 

 all known facts bearing on the movements of the enemy, 

 as such knowledge must precede any attempt to apply a 

 cure. 



So far as danger from the use of water is concerned, this 

 can be obviated by adding a wineglassful of paraffin to 

 three gallons of water. This proportion is sufficient to 

 destroy germinating spores, and will not injure, but in 

 reality benefit, the plants in other ways. 



Modes of Dissemination of Disease that can be 

 Prevented. — Dr. Erwin F. Smith, an American vegetable 

 pathologist, said, in a lecture on plant diseases, ' Competi- 

 tion is not likely to decrease, nor are prices likely to 

 advance very much, and the profits must come from 

 avoiding losses.' Hence the following suggestions : — 



Probably the commonest source of plant infection arises 



B 



