sh at the expense of the green
parts of roses, hops, maples, poplars, peas, and many other plants,
both in Europe and in North America, whilst in warmer latitudes the
genus _Meliola_ appears to take their place.

The _Elvellacei_ are fleshy fungi, of which the larger forms are
terrestrial; _Morchella_, _Gyromitra_, and _Helvella_ mostly growing
in woods, _Mitrula_, _Spathularia_, and _Leotia_ in swampy places, and
_Geoglossum_ amongst grass. The very large genus _Peziza_ is divided
into groups, of which _Aleuriae_ are mostly terrestrial. This group
includes nearly all the large-sized species, although a few belong to
the next. _Lachneae_ are partly terrestrial and partly epiphytal, the
most minute species being found on twigs and leaves of dead plants. In
_Phialea_ the species are nearly entirely epiphytal, as is also the
case in _Helotium_ and allied genera. Some species of _Peziza_ are
developed from the curious masses of compact mycelium called
_Sclerotia_. A few are rather eccentric in their habitats. _P.
viridaria_, _P. domestica_, and _P. hoemastigma_, grow on damp walls;
_P. granulata_ and some others on dung. _Peziza Bullii_ was found
growing on a cistern. _P. theleboloides_ appears in profusion on spent
hops. _P. episphaeria_, _P. clavariarum_, _P. vulgaris_, _Helotium
pruinosum_, and others are parasitic on old fungi. One or two species
of _Helotium_ grow on submerged sticks, so as to be almost aquatic, a
circumstance of rare occurrence in fungi. Other _Discomycetes_ are
similar in their habitats to the _Elvellacei_. The group to which the
old genus _Ascobolus_ belongs is in a great measure confined to the
dung of various animals, although there are two or three lignicolous
species; and _Ascophanus saccharinus_ was first found on old leather,
_Ascophanus testaceus_ on old sacking, &c. _Ascomyces_ is, perhaps,
the lowest form which ascomycetous fungi assume, and the species are
parasitic on growing plants, distorting the leaves and fruit,
constituting themselves pests to the cultivators of peach, pear, and
plum trees.

The _Sphaeriacei_ include a very large number of species which grow on
rotten wood, bark, sticks, and twigs; another group is developed on
dead herbaceous stems; yet another is confined to dead or dying
leaves. One genus, _Torrubia_, grows chiefly on insects; _Hypomyces_
is parasitic on dead fungi; _Claviceps_ is developed from ergot,
_Poronia_ on dung, _Polystigma_ on living leaves, as well as