MYCELIUM.

The Mycelium is commonly called the spawn of mushrooms.

It is the vegetative part of the fungus, and is composed of minute,
cylindrical, thread-like branching bodies called hyphæ. When we wish to
cultivate mushrooms we plant the spawn not the spores. The thread-like
branches permeate the earth or whatever the mushroom grows upon. The
color of the mycelium is generally white, but it may also be yellow or
red. Its structural details are only visible through a microscope.

Every fungus does not bear the spores exposed upon the cap nor
underneath it. The first group of Gasteromycetes, or “Stomach fungi,” as
Professor Peck has called them in his work on “Mushrooms and Their
Uses,” have the spore-bearing surface enclosed in a sac-like envelope in
the interior of the plant. The genus Lycoperdon belongs to this group,
and it contains the puff-balls so common in this country.

In the second group, Ascomycetes, or “Spore sac fungi,” the spores are
produced in delicate sacs called asci. The fruit-bearing part is often
cup-shaped, disc-like, or club-shaped, thicker at the top or covered
with irregular swellings and depressions like the human brain.

The Morels and Helvellas belong to this group. One often meets with
mushrooms of the former genus in the spring, and they are striking and
interesting looking fungi. There are many of both genera that are
edible. They will be described in detail later.