It may be accepted as true of the largest proportion of terrestrial species, that if they do not spring directly from rotten leaves, and vegetable débris in the last stage of decay, the soil will be rich in vegetable humus. A few only occur on sandy spots. The genus _Marasmius_ is much addicted to dead leaves; _Russula_, to open places in woods, springing immediately from the soil. _Lactarius_ prefers trees, and when found in exposed situations, occurs mostly under the shadow of trees.[A] _Cantharellus_, again, is a woodland genus, many of the species loving to grow amongst grass or moss, and some as parasites on the latter. _Coprinus_ is not a genus much addicted to woods, but is rather peculiar in its attachment to man--if such expression, or one even implying domesticity, might be employed--farmyards, gardens, dunghills, the base of old gateposts and railings, in cellars, on plaster walls, and even on old damp carpets. _Hygrophorus_ loves "the open," whether pastures, lawns, heaths, commons, or up the slopes of mountains, nearly to the top of the highest found in Great Britain. _Cortinarius_ seems to have a preference for woods, whilst _Bolbitius_ affects dung, or a rich soil. _Lentinus_, _Panus_, _Lenzites_, and _Schizophyllum_ all grow on wood. Coming to the subgenera of _Agaricus_, we find _Pleurotus_, _Crepidotus_, _Pluteus_, _Collybia_, _Pholiota_, _Flammula_, _Hypholoma_, and some species of _Psathyra_ growing on wood, old stumps, or charcoal; _Amanita_, _Tricholoma_, and _Hebeloma_ most attached to woods; _Clitocybe_ and _Mycena_ chiefly amongst leaves; _Nolanea_ amongst grass; _Omphalia_ and _Galera_ chiefly in swampy places; _Lepiota_, _Leptonia_, _Psalliota_, _Stropharia_, _Psilocybe_, and _Psathyrella_ mostly in open places and pastures; _Deconica_ and _Panæolus_ mostly on dung; _Entoloma_ and _Clitopilus_ chiefly terrestrial, and the rest variable.