THE AMERICAN BOTANIST. 
manufacture their own food. They are, therefore, obliged 
to live on food elaborated by other plants, and a decayingroot 
or moldering log is quite to their taste. In such a medium 
the fungus strands luxuriate until the plant is ready to pro- 
duce its spores. Then little whitish buttons or globes filled 
with, closely packed cells begin to appear here and there on 
the threads and, finally, after a good soaking rain, the tiny 
cells quickly absorb the moisture and the young puffball ex- 
pands and appears above the surface of the earth. It is still 
immature, however, and if broken open has the appearance 
of an unbaked loaf of bread, the interior being filled with a 
pure white, cheesy mass instead of the yellowish-brown 
spores. As the days pass the interior slowly changes in 
color, first to yellow and then to brown. Ultimately the 
outer skin breaks open and the multitudes of spores are ripe 
and ready to fly out in a smoke-like cloud at the slightest 
Botanists call the outer rind of the pufifball the per- 
idium and the cheesy mass within, the glcba. At maturity 
the gleba usually turns to a woolly mass in w^hich the spores 
are entangled. Under a microscope this is seen to consist of 
fine elastic hairs, to w^hich the name of capillitium has been 
given. The fungus threads that answer to the plant body 
form the mycelium. 
There are about fifty species of puffballs in the United 
States, and any locality is likely to contain several different 
kinds. By far tlie largest of these is the giant pufifball 
si^.nvn in .jur illustration. Ordinarily it is from eight to 
fifteen inches in diameter, but some truly gigantic specimens 
have been recorded. Mcllvaine mentions one from the 
Eastern States that measured three feet in diameter and 
weighed forty-seven pounds. Specimens four feet in 
diameter are reported from Europe. Its specific name of 
gigantea is, therefore, well deserved; in fact, this is probably 
