Index to Illustrations. 



FRONTISPIECE;. A wound parasite (Pleurotus ulmarins) on the trunk 



of a maple tree. Original. 

 FIG. i. The mycelium of a food-mold fungus. After Zopf ........... 8 



FIG. 2. Various special absorptive or sucker threads of parasitic 



fungi. After Zopf ........................................ 1 1 



FIG. 3. Fungus strands and storage organs. Original ............... 13 



FIG. 4. Storage organ of a cup-fungus with fruiting bodies. Original. 14 

 FIG. 5. Strands of mycelial threads of the dry-rot fungus. Original. . 15 

 FIG. 6. "Shoestring" strands of mycelial threads of the honey colored 



mushroom. Original .................................... 17 



FIG. 7. Highly magnified view of section through the end of mycelial 



strand of the honey-colored mushroom. After Zopf ...... 18 



FIG. 8. Fairy rings of a mushroom fungus. Photograph by Dr. F. 



Ramaley ................................................ 20 



FIG. 9. Chief kinds of spores of fungi. Highly magnified. After vari- 



ous authors . . . ........................................... 22 



FIG. ip. Various, kinds of common fruiting bodies of fungi. After 



various authors .......................................... 2 4 



FIG. ii. Kinds of spores produced by one rust fungus (wheat rust) at 



different times. Highly magnified. After various authors 25 

 FIG. 12. A carrion fungus. Original ........................ ........ . 29 



FIG. 13. A birds-nest fungus. After Engler and Prantl, and Sachs... 30 

 FIG. 14. Various explosive apparatuses for distributing spores. Mag- 



nified. After various authors ............................ 3 2 



FIG. 15. A caterpillar-fungus spore, germinating. By the author ..... 34 



FIG. 16. A dung-dwelling fungus of the black mold group growing on 



horse dung. Photograph by F. K. Butters ............... 37 



