LIFE HISTORIES OF FUNGI 275 
wind to the leaves of nearby barberry bushes, where they 
germinate. The resulting mycelium penetrates the epi- 
dermis, and ramifies between the cells of the leaf paren- 
chyma, from which it absorbs nourishment. Under 
certain circumstances, as for example in Australia where 
barberries do not grow, the barberry stage is eliminated. 
Soon this mycelium develops a reproductive structure 
called the pycnium (pycnidium or spermagonium), which 
breaks through the upper epidermis and produces innu- 
merable pycniospores (spermatia). The real nature of 
this structure is not known. 
OUTLINE OF LIFE HISTORY OF WHEAT RUST 
Rust on Grain 
44 
44 
Urediniospores (early summer) 
Teliospores (late summer) 
W-' 
4,4, 
Germination 
Rest (Nuclear fusion) 
44 
44, 
Mycelium 
Germination 
H 
4,4, 
Urediniospores 
Basidium 
44 
4- } Reduction 
Germination 
Sterigmata 
4,4, 
4 
Etc. 
Basidiospores (sporidia) 
4 
To barberry 
4 4 
Pycnia ^Ecia (Cell-fusion) 
4r I" "I" 
? /Eciospores 
44 
Rust on grain 
Near the lower epidermis are formed the "cluster- 
cups," or (Bcia 1 (aecidia). They break through to the 
1 Sing, cecium. 
