238 FUNGI. 
Myxocastres.—Rotten wood is one of the most favoured of 
matrices on which these fungi develop themselves; some of 
them, however, are terrestrial. Zthalium will grow on spent 
tan and other substances. Species of Diderma flourish on 
mosses, jungermannie, grass, dead leaves, ferns, &ce. Angiori- 
dium sinuosum, Grev., will run over growing plants of different 
kinds, and Spwmaria, 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. 
Nipuariacer grow on the ground, or on sticks, twigs, chips, 
and other vegetable substances, such as sawdust, dung, and 
rotten wood. 
The ConromyceTEs 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 Spheronemei, which are variable in their 
proclivities, although mostly preferring dead herbaceous plants 
and the twigs of trees. The exceptions are in favour of Spher- 
onema, 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 the stylosporous conditions of Spheria. They 
are mostly minute, and the stylospores are of the simplest kind. 
The Aelanconici have a preference for the twigs of trecs, burst+ 
ing through the bark, and expclling the spores in a gelati- 
nous mass. A few of them are foliicolous, but the exceptions 
are comparatively rare, and are represented chicfly in Glao- 
sporium, species of which are found also on apples, peaches, 
nectarines, and other fruits. The Toruwlacei are superficial, 
having much of the external appearance of the black moulds, 
