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from both sides. As soon as the petals had fallen, the trees were 

 sprayed with Bordeaux mixture to which Paris green was added. 

 Cheeks were left in all cases. The spraying was twice repeated later, 

 using the mixture of carbonate of copper and carbonate of ammonia. 



1 have felt for some time that these preparations of copper were 

 largely empirical and were not founded upon a sound scientific basis. 

 The two substances used in the Bordeaux mixture were both fungi- 

 cides, but when combined, the resultant bodies were only sulphate of 

 lime and oxide of copper, neither of which seemed well adapted for 

 the purpose. 



Consider for a moment how a fungous germ or spore develops. It 

 must first be deposited upon some portion of the living plant. This 

 happens in spring time through the spores that have retained their 

 vitality during the winter. They are set free by the warmth, mois- 

 ture and consequent decay of the debris of the previous season, and 

 float about in the atmosphere until they alight or rest upon the 

 growing plant. If they remain without moisture they do not develop, 

 but if moistened and kept wet for a few hours in a favorable temper- 

 ature, they vegetate and insert what may be called their roots into 

 the substance of the leaf bark or fruit, from which time they are able 

 to continue development independent of extraneous moisture. 



It is a well-known fact that in dry countries and also in dry seasons 

 fungi do but little harm, but their maximum efTects are found in 

 muggy, hot, showery periods. Dews and fogs are especially favora- 

 ble for fungoid development, and the popular belief is that such seasons 

 produce the fungi. This is of course incorrect inasmuch as they 

 exist only as a product of spores or seeds previously grown and 

 matured. A most convincing illustration is afforded by the effect 

 produced by an awning of any kind placed over a single grape trellis 

 in a vineyard where fungoid growth is prevalent. This awning 

 prevents the deposition of moisture upon the foliage immediately 

 underneath it from rain or dew, and although the floating spores 

 must necessarily be deposited there by 4he motion of the air, yet, 

 under this awning, they never develop. Such a trellis remains an 

 oasis of health In the midst of a desert of fungi. Now if the spore 

 must have water present in order to germinate and grow it, would 

 appear that if we could impregnate such water with some poisonous 

 substance we might prevent this action. In fact, it has been found 

 that many kinds of spores, and it is inferred that most of them, would 

 be influenced in this direction by the presence of various solutions. 



