xiv Minnesota Plant Diseases. 



FIG. 17. The same fungus as in figure 16, greatly enlarged. Micro- 

 photograph by F. K. Butters 38 



FIG. 18. An earth-dwelling fungus of the gill fungi. Original 39 



FIG. 19. A wood-dwelling fungus on a dead stick of wood. Original.. 40 



FIG. 20. A wound parasite. Original 46 



FIG. 21. A lichen. After Atkinson 48 



FIG. 22. A large witches'-broom on white pine. Photograph by R. S. 



Macintosh 52 



FIG. 23. Witches'-broom on balsam fir, caused by a rust fungus. 



Original 53 



FIG. 24. Witches'-broom on white spruce, caused by a mistletoe. 



Photograph by the author 54 



FIG. 25. An enlarged view of the broom on the spruce shown in 



Fig. 24. Photograph by the author 55 



FIG. 26. Birds-nest witches'-broom on red cedar, caused by a rust 



fungus. Original 57 



FIG. 27. Oat smut. An accomplished parasite. After G. P. Clinton.. 59 

 FIG. 28. An endophytic mycelium between the cells of a grass grain. 



By the author 60 



FIG. 29. Infection of a grass leaf by a rust fungus (wheat rust). 



After Ward - 61 



FIG. 30. Beetle fungi attached to an insect. After Thaxter 68 



FIG. 31. Various kinds of caterpillar fungi with fruiting bodies. Origi- 

 nal 70 



FIG. 32. Dead minnow with fish mold. Original 71 



FIG. 33. A spore-case of a fish mold, showing escaping swimming 



spores. Highly magnified. After Zopf 72 



FIG. 34. Damping-off of seedlings. After Atkinson. 77 



FIG. 35. Strawberry leaf spot. Original 79 



FIG. 36. Larch tree killed by the parchment pore-fungus. Original.. 81 



FIG. 37. Fungus galls on the leaves of Labrador tea. Original 83 



