dges of the cap, and
is afterwards reflected back over its whole surface.

MUSHROOM SPORES AND MYCELIUM.

The spore is the reproductive organ of the mushroom. It differs from the
seed of the flowering plant in being destitute of an apparent embryo. A
seed contains a plantlet which develops as such. A spore is a minute
cell containing a nucleus or living germ, the reproductive cell germ
called by some authors the germinating granule. This in turn throws out
a highly elongated process consisting of a series of thread-like cells
branching longitudinally and laterally, at length bifurcating and
anastomosing the mass, forming the vegetative process known as mycelium
or mushroom spawn.

On this mycelium, at intervals, appear knob-like bodies, called
tubercles, from which the mushrooms spring and from which they derive
their nourishment. See Fig. 5, Plate A.

Where the conditions have been unfavorable this mycelium has been known
to grow for years without bearing fruit.

Mushroom spores are very variable in size, shape, and color, but are
generally constant at maturity in the same genus. Their shape, almost
always spherical in the young plant, becomes ovate, ellipsoidal,
fusiform, reniform, smooth, stellate, sometimes tuberculate, or remains
globose. This feature, varying thus with the age of the plant, should be
studied in the mature plant.

MYCELIUM.

De Leveille has thus defined mycelium: "Filaments at first simple, then
more or less complicated, resulting from the vegetation of the spores
and serving as roots to the mushroom."

The mycelium of mushrooms or the mushroom spawn is usually white, but is
also found yellow, and even red. It is distinguished by some writers as
nematoid, fibrous, hymenoid, scleroid or tuberculous, and malacoid. The
nematoid mycelium is the most common. Creeping along on the surface of
the earth, penetrating it to a greater or less depth, developing in
manure among the debris of leaves or decayed branches, always protected
from the light, it presently consists of very delicate filamentous cells
more or less loosely interwoven, divided, anastomosing in every
direction and often of considerable extent.

Its presence is sometimes difficult to detect without the use of the
microscope, either on account of its delicacy or because of its being
intermingled with the organic tissues in which it has developed.

Sometimes mycelium unites in bundles more or less thick and branched.
This has b