ropical
countries.[D] Others are found growing amongst grass.

TRICHOGASTRES.--These are chiefly terrestrial. The rare but curious
_Batarrea phalloides_, P., has been found on sand-hills, and in
hollow trees. _Tulostoma mammosum_, Fr., occurs on old stone walls,
growing amongst moss. _Geaster striatus_, D. C., was at one time
usually found on the sand of the Denes at Great Yarmouth. Although
_Lycoperdon giganteum_, Batsch, occurs most frequently in pastures, or
on hedge banks in fields, we have known it to occur annually for
some consecutive years in a garden near London. The species of
_Scleroderma_ seem to prefer a sandy soil. _Agloeocystis_ is rather
an anomalous genus, occurring on the fruit heads of _Cyperus_, in
India. _Broomeia_ occurs at the Cape on rotten wood.

MYXOGASTRES.--Rotten wood is one of the most favoured of matrices on
which these fungi develop themselves; some of them, however, are
terrestrial. _AEthalium_ will grow on spent tan and other substances.
Species of _Diderma_ flourish on mosses, jungermanniae, grass, dead
leaves, ferns, &c. _Angioridium sinuosum_, Grev., will run over
growing plants of different kinds, and _Spumaria_, in like manner,
encrusts living grasses. _Badhamia_ not only flourishes on dead wood,
but one species is found on the fading leaves of coltsfoot which are
still green. _Craterium_ runs over almost any substance which lies in
its way. _Licea perreptans_ was found in a cucumber frame heated with
spent hops. One or two _Myxogastres_ have been found on lead, or even
on iron which had been recently heated. Sowerby found one on cinders,
in one of the galleries of St. Paul's Cathedral.

NIDULARIACEI grow on the ground, or on sticks, twigs, chips, and other
vegetable substances, such as sawdust, dung, and rotten wood.

The CONIOMYCETES consist of two sections, which are based on their
habitats. In one section the species are developed on dead or dying
plants, in the other they are parasitic on living plants. The former
includes the _Sphaeronemei_, which are variable in their proclivities,
although mostly preferring dead herbaceous plants and the twigs of
trees. The exceptions are in favour of _Sphaeronema_, some of which are
developed upon decaying fungi. In the large genera, _Septoria_,
_Ascochyta_, _Phyllosticta_, _Asteroma_, &c., the favourite habitat is
fading and dying leaves of plants of all kinds. In the majority of
cases these fungi are not autonomous, but are merely th