.xiv CONTENTS. 



CHAPTER IV. 

 i LO. NATUEAL AND ARTIFICIAL INFECTION, 50 



PAGE 



CHAPTER V. 

 11. DISPOSITION OF PLANTS TO DISEASE, 58 



CHAPTER VI. 



S 1 PREVENTIVE AND COMBATIVE MEASURES, - 63 



I. EXTERMINATION AND REMOVAL OF THE PARASITIC 



FUNGI ALONE, 65 



II. REMOVAL AND DESTRUCTION OF DISEASED PLANTS, - 71 



III. AVOIDANCE OR REMOVAL OF CONDITIONS WHICH FAVOUR 



INFECTION. - 75 



IV. SELECTION OF HARDY VARIETIES, 81 



CHAPTER VII. 

 S 13. ECONOMIC IMPORTANCE OF DISEASES OF PLANTS, 83 



CHAPTER VIII. 

 SYMBIOSIS: MUTUALISM, 86 



/~ 



f* 



CHAPTER IX. 



NUTRICISM, - 92 



me MYCORHIZA, 93 



rk 



ic MYCORHIZA, 97 



-ODOll 



v OF THE ALDER, ETC., 99 



; 



OF THE LEGUMINOSAE, - - 101 



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