tion: Figure 5.--Small portion of a stem of a morel showing
cell filaments. Highly magnified.--_Longyear._]

If the cap or stem of a mushroom is examined with a microscope of high
magnifying power it will be found to be made up of a continuation of the
mycelial filaments, interlaced and interwoven, branching, and the
tubular filaments often delicately divided, giving the appearance of
cells. Figure 5 represents a small portion of a Morel stem highly
magnified showing the cell filaments. In soft fungi the mycelial threads
are more loosely woven and have thin walls with fewer partitions.

The _veil_ is a thin sheet of mycelial threads covering the gills,
sometimes remaining on the stem, forming a _ring_ or _annulus_. This
sometimes remains for a time on the margin of the cap when it is said to
be _appendiculate_. Sometimes it resembles a spider's web when it is
called _arachnoid_.

The _volva_ is a universal wrapper, surrounding the entire plant when
young, but which is soon ruptured, leaving a trace in the form of scales
on the cap and a sheath around the base of the stem, or breaking up into
scales or a scaly ring at the base of the stem. All plants having this
universal volva should be avoided, further than for the purpose of
study. Care should be taken that, in their young state, they are not
mistaken for puff-balls. Frequently when found in the egg state they
resemble a small puff-ball. Figure 6 represents a section of an Amanita
in the egg-state and also the Gemmed puff-ball. As soon as a section is
made and carefully examined the structure of the inside will reveal the
plant at once. There is but little danger of confusing the egg stage of
an Amanita with the puff-ball, for they resemble each other only in
their oval shape, and not in the least in their marking on the surface.

[Illustration: Figure 6.--The lefthand figure represents a vertical
section through a young plant of the gemmed puff-ball showing the
cellular structure of the stem-like lower half, called the subgleba. The
righthand figure shows a vertical section of the egg stage of an
Amanita, a very poisonous fungus which grows in woods and which might be
mistaken for a young puff-ball if not cut open. The fungus forms just
below the surface of the soil, finally bursting the volva, sending up a
parasol mushroom. Natural size.--_Longyear._]

=WHAT IS A FUNGUS OR A MUSHROOM?= It is a cellular, flowerless plant,
nourished by the mycelium which permeat