By reference to this figure some of the special characteristics of the group can be observed. There are mushrooms in other genera which show a volva or sheath at the base of the stem, and which contain edible species, but in these the stem is ringless. The Volvariae, for instance, show a conspicuous volva, a stem that is ringless, and pinkish spores. The Amanitopsis vaginata carries a volva, but no ring. The spores are white, as in the Amanita. In gathering mushrooms either for the table or for the herbarium, care should be taken not to leave any portion of the plant in the ground, so that no feature shall be lost that will aid in characterizing the species. In the careless pulling up of the plant the volva in the volvate species is often left behind. AGARICINI. Fries. LEUCOSPORI (SPORES WHITE, OR YELLOWISH). _Genus Russula_ Fr. The _Russulae_ bear some resemblance to the _Lactars_, their nearest allies, but are at once distinguished from them by their want of milk. They are very abundant in the forests and open woods. The genus is cited by some authors as the most natural of the agarics, but, as many of the species very closely resemble each other, it requires careful analysis to determine them. The plants of this genus are not volvate, and have neither veil nor ring. The hymenophore is not separate from the trama of the gills. Although some are pure white, the caps are usually brilliant in coloring, but the color is very susceptible to atmospheric changes, and after heavy rains the bright hues fade, sometimes only leaving a slight trace of the original coloring in the central depression of the cap. The cap in youth is somewhat hemispherical, afterwards expanding, becoming slightly depressed in the centre, somewhat brittle in texture; gills rigid, fragile, with acute edge; stem thick, blunt, and polished, usually short. The spores are globose, or nearly so, slightly rough, white or yellowish, according to the species. In R. virescens the spores are white, while in R. alutacea the spores are an ochraceous yellow in tint. A number of the species are of pleasant flavor, others peppery or acrid. Out of seventy-two described by Cooke, twenty-four are recorded as acrid. With some of these the acridity is said to disappear in cooking, and a few mycophagists claim to have eaten all varieties with impunity. We have recorded, however, some well authenticated cases of serious gastric disturbance, accompanied by acute inflammation of the mucous membrane, caused by the more acrid of these, notably _R. emetica_ and _R. foetens_, and in view of this fact it would seem a wise precaution for the _amateur_ collector to discard or at least to use very sparingly all those which have an acrid or peppery taste, until well assured as to their wholesomeness.