Index to Illustrations. 



Frontispiece. A wound parasite (Pleurotus ulmarius) 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 ot 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. 10. Various kinds of common fruiting bodies of fungi. After 



various authors 24 



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 32 



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 



