Minnesota Plant Diseases. xv 



FIG. 38. Two ways in which wood is destroyed by wood-rot fungi. 



Highly magnified. After Hartig 86 



FIG. 39. A good example of an epidemic. Potato-blight has within 

 a week entirely destroyed the potato plants in this field. 



After Clinton 99 



FIG. 40. An epidemic of mildew on cucumbers checked by spraying. 



After F. C. Stewart 101 



FIG. 41. A lowly algal fungus. Highly magnified. After Schroeter. . 105 

 FIG. 42. Water and fish molds. Highly magnified. After various 



authors 106 



FIG. 43. Sewer-pipe fungi. Highly magnified. After Pringsheim. ... 108 



FIG. 44. Downy mildews. Highly magnified. After De Bary 109 



FIG. 45. A downy mildew with the aspect of a white rust. Original. . in 



FIG. 46. A black mold. Highly magnified. After Zopf 113 



FIG. 47. An insect mold. Highly magnified. After Brefeld 115 



FIG. 48. Yeast fungus cells. Highly magnified. After Rees 118 



FIG. 49. Plum-pocket fungus and loose-weft fungus. Highly magni- 

 fied. After De Bary and Sachs 121 



FIG. 50. A powdery mildew on common plantain leaf. Original 124 



FIG. 51. The fruiting body of the powdery mildew of black haw, show- 

 ing the appendages. Highly magnified. Microphoto- 



graph by E. W. D. Holway 125 



FIG. 52. The fruiting body of the powdery mildew of willows, show- 

 ing the appendages and spore-sacs. Highly magnified. 



Microphotograph by E. W. D. Holway 126 



FIG. 53. Ergots of grasses. Original 127 



FIG. 54. Ergot fungus on canary grass. Original 128 



FIG. 55. Fruiting bodies and spores of the ergot fungus. Variously 



magnified. After Tulasne and Brefeld 130 



FIG. 56. A caterpillar fungus. Original 131 



FIG. 57. A strangling fungus on grass leaves and stems. Original. . . . 132 



