h has to be done in the absence of an
American manual or textbook. A great deal has been written for us, it is
true, by experienced botanists, but a general and comprehensive work has
yet to be compiled.

Before we begin our list of fungi, let us learn what a mushroom is, and
know something of its component parts. A mushroom consists of a stem and
a cap, or pileus. The cap is the most conspicuous part. The color varies
from white and the lightest hues of brown up to the brightest yellow and
scarlet. Its size is from an eighth of an inch to sixteen inches and
more in diameter. The surface is smooth or covered with little grains
(granular) or with minute scales (squamulose) shining like satin, or
kid-like in its texture. It may be rounded and depressed (concave),
elevated (convex), level (plane), or with a little mound in the centre
(umbonate). It may be covered with warts, marked with lines (striate),
or zoned with circles. The margin may be acute or obtuse, rolled
backward or upward (revolute), or rolled inward (involute); it may be
thick or thin.

THE STEM.

The stem is the stalk that supports the cap. It is sometimes attached to
one side, and then it is said to be lateral or between the centre and
side, and it is called eccentric; when it is in the middle, or nearly
so, it is central.

It is either solid, fleshy, stuffed with pith, or hollow, fibrous, firm
and tough (cartilaginous). It is often brittle and breaks easily, or it
will not divide evenly in breaking. Its color and size both vary, like
the cap. It may taper toward the base, or toward the apex, be even or
cylindrical. Its surface may be smooth (glabrous), covered with scales
(squamulose), rough (scabrous), dotted, lacerated, or be marked with a
network of veins (reticulated). The base may be bulbous, or only swollen
(incrassated), and it may root in the ground.

[Illustration: Sections of gill bearing mushrooms.

Gills adnexed
Gills free
Gills adnate
Gills decurrent
Gills sinuous
Gills serrated

Pileus umbonate
Pileus umbilicate

Margin involute
Margin revolute]

THE GILLS.

The gills or lamellae are the radiating parts, like knife blades, that
extend from the centre to the margin underneath the cap. They contain
the spores. The group of mushrooms that have gills are called Agaracini
or Agarics. The gills vary in color; sometimes they change color when
mature. When they are close together they are called crowded,