THALLOGENS. 251 
ConORT. CHARACTERISTICS. . SUB-ORDEPS. EXAMPLES. 
f Spore cases plunged ) 
I, Tubercularini. in an entangled recep- \ fusarium. 
. ( Spore on a 
es na : 
: amentous recepta- 
be # t sig te IT. Mucorini. 4 cle, at first inclosed in > Stilbum. 
IV. ConcoMYCETEs. ncacetpecbe gig asst (alittle peridium. 
cellular; the thal- Spore cases at first 
pn often imper- ; 17, Macedines. Jconcealed by fila- > Aspergillus. 
P ments. 
Spore cases spring- j 
IV. Hypodermi, ~ing from under the ¢ Exasporium, 
' cuticle of trees, 
Musurooms (AGARICS). 
The Mushrooms, then, are leafless, stemless, and rootless; they 
respire, thereby producing carbonic acid, like flowers and animals. 
e organs of vegetation and those of reproduction are quite dis- 
tinet in the mushrooms. The first are composed of a sort of pack- _ 
ing, consisting of very thin intercrossing filaments, which are 
termed Mycelium. This mycelium is subterranean, not very 
apparent, and often doomed to immediate destruction. It is upon 
the mycelium that the apparatus of reproduction, so closely con- 
nected with the organs of vegetation, develops itself. i 
multiplicity of reproductive organs is recognised in certain species 
of which we shall have occasion to speak. The Erysiphe, which 
attack the Pea, and the Oidium Tuckheri, which attacks the Vine, 
is supposed to be a particular state of Erysephes, in which are noted 
three distinct kinds of reproductive apparatus, which develop 
themselves in succession. 
Mushrooms exist under the most opposite conditions, and in every 
kind of locality. Some appear on the surface of the earth, as the 
cultivated Mushroom, the edible Boletus, the Morel, the Puff-ball, 
c. Some grow upon the trunks of trees, upon branches, and 
upon leaves; others, as the Truffle, are found buried in the earth 
. a considerable depth. Thousands of small species live as para- 
sites upon other plants ; the Oidiwm Tuckeri on the Vine, Botrytis 
infestans on the potato. Others attack animals. No one is 
‘gnorant that the malady which destroyed so many silkworms in 
’ € nurseries in the south of France was produced by a Fungi 
which developed itself in the interior of the living larve. Jn short, 
these microscopic and encroaching objects attack even the skin 
