XX I N T R O , D U C T I O N.
The Boletus elegansf, which was found in the hollow of an old elm
tree root, in Auguit,. 1786, did not make its appearance there in 1787,
but this pieient year 1788, on the 28th of July, another fpecimen grew
in the felf fame fpot | fo that this fpecies feems to be biennial in its
nature..
Some fpecies of Fungi are fubjedt, from accidents, in foil, fituation,
and expofure, to vary much in point of fize: I have feen fpecimens of the
Lycoperdon bovifta, varying from the iize of a walnut to that of a child's
head, when the fmall, as well as the large fpecimen, had arrived at its. full
extent of growth.
July 18, 1788, the Agaricus latusS was brought me, in a ftate of uncommon
luxuriance. The pileus meafured twenty-feven inches in circumference,
the furface was waved, and the margin undulated; a gill of
the firft ieri.es meafured three inches and two lines in length, and fomething
more than one inch in breadth; the item was near feven inches
high, and about four in circumference; the feeds were of a brown colour,
and ipherical.
In September, 1787, I gathered a fpecimen of the Agaricus mufcarius,
which weighed thirty-one ounces and upwards, though the lower part of
the item and the root were wanting. Happily however, this inequality
of iize is not very productive of error in the detedion of fpecies; for the
fubftance, texture, conftituent matter, and generally the colour too, are
often exaftly fimilar, and undergo the fame mutations in the fmaller, as
in the larger fpecimen.
In regard to the items of Agarics, the circumftances of folid and fibular,
ihould be attended to with caution, before they can be properly applied
as difcriminative charadters ; becaufe in many fpecies the item is
folid in the firil ftages of growth, but becomes fiftular, by degrees, when
the plant arrives to. its perfedt ftate; and, in the progrefs of decay, becomes
f Tab. 76.1 g Tab, I.
I N T R O D U C T I O N . xxi
comes more and more hollow, till its final diifolution. In defcrxbing
the plants, in this work, I have carefully noted thefe changes: but all
items of this kind are to be confidered as folid, when that circumftance is
made ufe of, by way of fpecific chara&er; and where it is faid, that a
item is Jolid, it is meant, when the plant is in a ftate of growth and
vigour; when it is faid, that a item is fiftular, it is to be underitood from
its firit appearance above ground.
I have endeavoured in all the figures, to give proper attention to the
Roots of the Agarics j a part of them which feems to have been greatly
neglefted, though moit of the fpecies are furniihed either with a proper,
or a common root. It generally confifts of a tuberous piece, of a proportionable
fize, and a tough hard fubftance; which is, as it were, incorporated
into the bafe of the item, and emits fibres into the ground or other
matter, for the fupport of the plant. It is often, however, overlooked,
for if the plant is not taken up with care, the bafe of the item breaks,
and the root,, with its fibres», remains in. the ground, and efcapes our
noticc, _ .
Figure,, in the Pileus o f Agarics, which has by many been confidered
as a charader of fpecific diftindtion, has been a fource of much perplexity;
the truth of this aifertion will be obvious, when we confider,.
that in many fpecies the feveral Terms, globular, oval, convex,, umbeliicated,
and funnel-ihaped, may, with equal propriety, be applied to the
fame individual fpecimen, in the various itages of its growth. Thefe.
mutations of figure are carefully noted, throughout the work, both on the
plates and in the defcriptions; and where the figure of the pileus is
brought in, as aiding to the fpecific charadter, it is meant,.to denote its
figure when in a ftate of perfedt growth,, or between the.laft excefs of its,
increafe, and the firil approaches.of its,decay. Laceration.or rents in the
pileus, which are always a certain fign.of its approaching decay, are the
eftedt of contraction in its fubitance, and depend in fome meafure on the
drynefs or moifture of the.air; for.in.rainy feafons,. when the plant can
imbibe;