60 BOTANY. 
The plants of this order are remarkable as esculents, as poisonous sub- 
stances, and as causing great injury to animal and vegetable tissues. It 
is among these that we find the various mushrooms, some known as furnish- 
ing an excellent article of food, others as highly poisonous. It is difficult 
to indicate any good character by which to distinguish the former from 
the latter, other than that they generally grow solitary in dry pastures, 
are rarely high colored, generally white or brownish, seldom show scales, and 
have brittle flesh. The various moulds which occur on animal or vege- 
table substances belong to this order. Some fungi are produced on living 
animals. 
Sub-order 1. Phycomycetes: Thallus floccose, spores surrounded by a 
vesicular veil, or sporangium. The principal genera are Phycomyces and 
Mucor. i 
Sub-order 2. Ascomycetes: Sporidia (spores), contained often in sets of 
eight in asci or tubes. This sub-order includes the Truffle, Tuber cibarium 
(pl. 54, fig. 18). , 
Sub-order 3. Hyphomycetes: Thallus floccose, spores naked, often septate. 
Sub-order 4. Coniomycetes : Flocci of the fruit obsolete or mere peduncles, 
spores single, often partitioned, and on more or less distinct sporophores. 
The principal genera in this sub-order are Ustilago and Uredo, the latter 
causing the well-known smut and brand. PI. 54, fig. 16, Ustilago segetum ; 
fig. 17, Uredo phaseolli. 
Sub-order 5. Gasteromycetes: Hymenium inclosed in a membrane (peri- 
dium), spores as in the next sub-order. A species of Bovista one of the 
principal genera. B. gigantea (pl. 54, fig. 19) is remarkable for its great 
size and for the rapidity of its growth; having been known to increase in a 
single night from the size of a pea to that of a melon. Pl. 54, fig. 20, repre- 
sents Morchella esculenta, an edible fungus which is prepared in large 
quantities in some parts of Europe, by cutting into pieces and drying in 
ovens. : 
Sub-order 6. Hymenomycetes: Hymenium naked, spores in sets of four, 
and borne on distinct sporophores. Hydnum auriscalpium and squamatum 
(pl. 54, fig. 23). Polyporus perennis (pl. 54, fig. 21). <A species of 
Polyporus, P. destructor, is one of those Fungi which cause the dry rot. 
Boletus umbellatus (pl. 54, fig. 22°); B. edulis (fig. 22’); Cantharellus 
cibarius (fig. 24); Agaricus fimetarius (fig. 25); A. campestris and squar- 
rosus (fig. 26); A. procerus (fig. 27); and A. muscarius (fig. 28). The 
genus Agaricus contains a great number of species, and includes some that 
are highly poisonous, as well as others that are perfectly harmless. The com- 
mon mushroom belongs here. 
Orper 3. Licueness, the Lichen Family. Plants forming a thallus, which 
is either foliaceous, crustaceous, or pulverulent, these different forms de- 
pending on the mode in which the cells are developed and combined. The 
reproductive organs appear on the frond in the form of protuberances of 
various kinds, consisting of an outer layer of thick-walled roundish cells, 
more dense than the tissue of the thallus, and of a different color; and 
of an internal medullary layer of paraphyses and sporangia, lying 
60 
