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 _Aleuriæ_ are mostly terrestrial. This group includes nearly all the large-sized species, although a few belong to the next. _Lachneæ_ 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. episphæria_, _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 _Sphæriacei_ 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 some species of _Stigmatea_ and _Dothidea_. Of the genus _Sphæria_, a considerable number are found on dung, now included by some authors under _Sordaria_ and _Sporormia_, genera founded, as we think, on insufficient characters. A limited number of species are parasitic on lichens, and one species only is known to be aquatic. [Illustration: FIG. 109.--_Torrubia militaris_ on pupa of a moth.]