PUFFBALLS AND RELATED FORMS (GASTEROMYCETES) 391 
A very interesting Puffball is the Earthstar (Geaster) shown in 
Figure 347. In this form the outer layer of the peridium splits 
into regular segments and these segments are hygroscopic. 
When the segments are wet they bend back and downward and 
in this way the outer layer 
of the peridium spreads out 
like a star. The inner layer 
of the peridium opens by an 
apical pore and allows the 
spores to escape as in other 
Puffballs. 
The Bird’s Nest Fungi 
(Fig. 3848), which are close 
relatives of the Puffballs, Paty 
show another interesting fe:- pai ears 
ture. They are small, usu- Suite ais Ss for 
: FIG. . — Puffballs, coper 3 
ally: less than centmeter Three have opened at ret thus 
in height and width. They allowing the spores produced in the in- 
develop on twigs and sticks terior to escape. }. 
as well as on organic matter 
that is quite well decayed. One often finds them growing on the 
benches in greenhouses. The chambers of the gleba become 
Fic. 347. — An Earthstar, Geaster. About natural size. 
enclosed in walls and separate. After the peridium opens, the 
sporophore is cup-shaped and, with the egg-like chambers of the 
gleba exposed, resembles a bird’s nest full of eggs. 
The Stink Horn (Fig. 349), noted for its intolerable odor, is 
another Fungus of this order. Its mycelium feeds on decaying 
