TOADSTOOLS 229 
lar layer, and when mature become ruptured by the rapid 
growth of their central tissues, resulting in the formation 
of a stalk which carries up the slimy mass of spores to 
some distance above the ground. The intolerable odor 
of most of the species has earned for them their inelegant 
but quite appropriate common name. 
384. The Toadstools (Order AGArIcALES). The fruits 
of these plants in some respects are the highest of the 
Carpomyceteae. They are not only of considerable size 
(ranging from 1 to 20 centimeters, or more, in height), 
but their structural complexity is so much greater than 
that of the other orders that they must be regarded as the 
highest of the fungi. Like the Puff-balls, they produce 
an abundance of vegetative filaments (mycelium) under- 
ground or in the substance of decaying wood. These 
filaments are loosely interwoven, becoming in some cases 
densely felted into tough masses or compacted into root- 
like forms. While mostly saprophytic some appear to be 
parasitic, especially on the woody tissue of trees which are 
rotted by them. Sooner or later these underground 
filaments produce the spore fruits, which are mostly 
umbrella-shaped, as in common Toadstools and Mush- 
rooms, or of various more or less irregular shapes, as in 
the Pore fungi, Coral fungi, etc. 
385. The Mushrooms of the markets (Agaricus cam- 
pestris) so commonly cultivated by yardeners, may illus- 
trate the mode of development of the Toadstools (Family 
Agaricaceae). The vegetative filaments compose the so- 
called “‘spawn”’ which grows through the decaying matter 
from which it derives its nourishment. Upon this at 
length little rounded masses of filaments arise, which be- 
come larger and larger and are the young fruits. The 
circular spore-bearing layer is first internal and subter- 
ranean as in the Stink-horns, but it is brought above 
