ILLUSTRATIONS 



PAGE 



Apple-scab on leaves (after Wallace) 6 



Apple-scab on fruit 7 



Cluster of scabby apples . 8 



Apple-scab on young fruits . 9 



Bitter-rot of apples 16 



Bitter-rot cankers . . . 17 



Stippen, or bitter-pit 25 



Frost-injured apple-tree 37 



Apple-tree showing crotch-injury 38 



Black-rot of apple. Early stages ....... 47 



Black-rot mummy . . ... . . . . . .48 



Leaf -spot of apple . . . 49 



Black-rot canker . . . 50 



Apple-blotch, early stage . . .- . . . .58 



Apple-blotch, late stage -59 



Apple-blotch cankers . 60 



Apple-rust on leaves ........ : 65 



Cedar-apples, winter condition 66 



Cedar-apples, spring condition ........ 67 



Fruiting body of the white heart-rot pathogene .... 72 



White heart-rot ; cross-section of an affected limb . . . .73 



Blister-canker, apple'. 77 



Northwestern anthracnose cankers .83 



Apple fruit-spot } " . . , . . . 89 



Soft-rot, or blue-mold . . .... . . . . . 92 



Armillaria root-rot (after Douglass) . .... . . 98 



Arurillaria root-rot fungus ; rhizomorphs and young sporophores . 99 



Sooty-blotch of apple '. . ,: ,~ 105 



xvii 



