MUSHROOI\rS. 199 
n lichen. The order Lichen has sometimes been included under one 
genus called Lichen, and placed in the order AlgcE. 
Order Fungi, or mushrooms 
The 6th Order contains the Mushrooms, or fungus plants ; these 
never exhr.jit any appearance of green herbage ; they are generally 
corky, fleshy, or mould-like, varying much in ionu and colour. Thu 
fruit of some is external, of others internal. They are often of very 
quick growth and short duration. The genus Agaricus, which con- 
tains the common eatable mushroom, has a convex, scaly, white 
head, called a pileus ; this is supported on a stalk called a stipe. 
On the under surface of the pileuSj or cup, are seen many flesh-col- 
oured membranes called gills. These gills, in the young state of the 
mushroom, are concealed by a wrapper called a volva, which is con- 
sidered as a kind of calyx. As the mushroom becomes older, the 
volva bursts and remains upon the stipe, while the pileus, released 
from its confinement, extends upwards and exhibits an uneven ap- 
pearance upon its edge, caused by its separation from the volva. 
Fig. 157 represents the most 
important parts of the mush- 
Fig. 157. ^^^BH^^^^^^ room ; a, the gills running 
m^^^^m^^^^ from the stipe to the circum- 
ference, under the pileus ; b, 
a young mushroom, with the 
pileus of a globular form, 
and not separated from the 
volva ; c, the volva, or wrap- 
per, bursting and separating 
from the pileus so as to ex- 
hibit the gills beneath; d, 
part of the volva remaining 
upon the stipe in a circular form, and called an annuhis, or ring. 
"If the mushroom be left for a time on a plate of glass, a powder 
will be found deposited; this is the seed,* or organic germ. That 
these are capable of germination, is evident to cultivators, who now 
form mushroom beds, by strewing the decayed plants on prepared 
beds of manure."! 
A species of the genus Agaricus is common in Italy, and much 
valued for food ; it is of a fine red or orange-colour ; the ancient 
Romans esteemed it as a great luxury. The genus Boletus conta'ms 
the touchwood, or spunk, which is sometimes used as tinder. The 
Lycoperdon contains the puff'-ball. 
The Cryptogamous plants are probably the least understood of 
all the visible works of nature. Philosophers have asserted that 
some of this race do not belong to the vegetable, but to the animal 
kingdom ; having discovered insects in mushrooms, they say, like 
the sponge and the corals, these should be classed among animal 
productions. Few, however, at present, entertain this belief ; and 
the fact of their having been raised from s^'^d sprinkled on the earth, 
proves them to be of vegetable growth, a curious field of inquiry 
presents itself in the consideration ol ' iiflTerence between animal 
and vegetable Hfe. This we shall herealter partially examine; not, 
however, expecting to decide upon this subject, for in our researches 
* Called sporules. t Nuttall. 
Order Mushrooms— Explain Fia;. 157— Mush roonis capable of germination— Differ- 
em genera — Opinions of some philosophers respecting the Cryptogamous ulants. 
