II. PUFF-BALLS. 
Puff-balls belong to a class of fungi to which botanists give the 
name Gasteromyceteae, “stomach fungi”—a name suggested by 
the fact that.their spores are produced within the receptacle, or 
spore-bearing part. In most of them, the whole interior of the 
mature plant is filled with a dusty mass of spores, intermingled 
in many cases with minute threads or filaments. They are 
among the most easily recognized of our fungi, and the larger 
ones in their early state are among the best of our edible species. 
Almost every one, whether botanist or not, confidently thinks 
he knows a puff-ball when he sees it. Over and over again, the 
little globular growths consisting of a papery envelope stuffed 
full of brown dust and cottony filaments have been seen lying 
singly or in clusters on the ground, or adhering to the decaying 
wood of old stumps or prostrate trunks of trees. Often in child- 
hood days these have been subjected to sudden pressure between 
the thumb and fingers, that there might be seen the little cloud. 
of dust-like spores that is thereby ejected, and that quickly van- 
ishes in the air like a little puff of smoke. 
No one would think these good to eat, and indeed they are 
not, when in this condition. Nearly all puff-balls are white with- 
in when young, and their substance is then of a soft, fleshy con- 
sistence, very unlike the dusty filamentous material that fills 
therm when mature. And it ts only while they are white within 
that they are fit for food. When they reach maturity, the flesh 
at first assumes greenish-yellow or brownish-yellow hues. They 
are then spoiled for eating. Soon they become moist within, and 
when this moisture dries away, the whole interior (except in 
some species a small cellular part at the base) is found to be 
transformed into the usual dusty brown mass that characterizes 
the mature puff-ball. 
There are in this country many species of the genus Lycoper- 
don, to which most of our puff-balls belong; probably not less 
than forty. They may be arranged in two groups. In one group 
the plants are commonly small, rarely exceeding an inch and a 
half or two inches in diameter. These, when mature, burst at 
the top, in a somewhat circular but rather ragged aperture, to 
permit the spores to escape. The other group, to which generic 
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