280 STRUCTURE AND LIFE HISTORIES 
with the gills down over a piece of white paper, and left 
for a few hours, a dark purplish deposit will form in lines 
under each gill. With Amanita the color is white. This 
deposit (the " spore-print ") is composed of spores, shed from 
the surfaces of the gills (Fig. 202). Microscopic examina- 
FIG. 204. The meadow mushroom (Agaricus campeslris, var. Colum- 
bia.) Young fruiting bodies (carpophores). The mycelial hyphae arc in 
the substratum. (Photo by G. F. Atkinson.) 
tion discloses the fact that the gills are composed of a net- 
work of hyphae. Their surface is covered with innumer- 
able short, thick, club-shaped bodies, filled with proto- 
plasm (Fig. 203) . These are the basidia (singular basidium) . 
Fungi which bear basidia are grouped together as Basidio- 
mycetes. At the tip of each basidium are two tiny projec- 
