that floated away when they played football with a mature pnff 

 ball in the cow pasture ? This smoky powder is composed of 

 innumerable small bodies called spores. The toad stool is one of 

 the highest representativ^es of this great tribe of flowerless plants. 

 The majority of the plants of this class are small and inconspicuous. 

 Farmers detect their presence rather by their injurious effects than 

 by the recognition of the individual plant. 



13. A fungus may grow on the surface of the host jjlant {the 

 jplant upon which it feeds) or it may grow heneath the surface and 

 within its tissues. — We have, therefore, two classes of fungous ene- 

 mies, in a broad way : the surface feeders and the internal feeders. 

 The " smuts " of corn, oats and wheat, the " black knot " of the 

 plum and cherry are examples of the deep-seated class, while the 

 mildew of the gooseberry and the cherry are common examples of 

 the surface-feeding types. 



H. /Spores, like seeds, germinate under the influence of favor- 

 able conditions of heat and moisture, and the plani parasite works 

 or grows from the outside inwards. — The way in which spores ger- 

 minate and become established on the host plant gives a clew to the 

 best ' methods of fighting this type of enemy. The spore must 

 either be killed or its germination prevented. Experiment Station 

 workers and fruit-growers found years ago that soaking wheat in 

 blue stone would largely prevent smut. Blue stone, or blue vitriol, 

 known to chemists by tlie name of copper sulfate, is now recognized 

 as the base of the most valuable fungicide in use. This fungicide 

 is called Bordeaux mixture. Full instructions for its preparation 

 and use are given in Bulletin 114, Cornell University Experiment 

 Station. To prevent the germination of the spores which give I'ise 

 to the plant disease causing the spots and scabs on apples, the trees 

 are completely covered in early spring with a spray of Bordeaux 

 mixture. Tlie more complete the covering, provided it is a23plied 

 before growth begins in the spring, the cleaner will be the fruit and 

 foliage. These sprayings are repeated during the spring and early 

 summer. 



15. Plant parasites of the orchard usually infest hothfrtdt and 

 foliage. — Spraying is an insurance. The grower may, and often 



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