Fig. 11. Ascus, sporidia, and paraphyses. The Morchella _deliciosa_ is highly esteemed as an esculent wherever eaten. Split open and stuffed with bread crumbs seasoned with pepper, salt, and butter and a pinch of thyme or onion, steamed in a hot oven, and served with butter sauce, this mushroom makes a very savory dish. _Note._--Small specimens have been selected for illustration in this plate in order to utilize as much as possible the plate space. [Illustration: Plate IV. THE NORRIS PETERS CO., PHOTO-LITHO., WASHINGTON, D. C.] PLATE IV. STRUCTURE OF THE AGARICINI, GILL-BEARING MUSHROOMS. Fig. 1. Cap or pileus umbonate, _a_; stem or stipe fistulose, tubular, _b_; gills or lamellae adnate, and slightly emarginate. Fig. 2. Gills remote, _i. e._, distant from the stem. (See _a_.) Fig. 3. Gills adnexed, partly attached to the stem at their inner extremity, _a_. Fig. 4. Gills emarginate, with a tooth, as at _a_; stem stuffed. Fig. 5. Cap obtuse, _e_; gills free, _i. e._, reaching the stem but not attached thereto (see _a_); _b_ stem stuffed. Fig. 6. Cap umbilicate, slightly depressed in the centre, _b_; gills decurrent, _i. e._, running down the stem. (See _a_.) Fig. 7. Basidium, cell _a_, borne on the hymenium, or spore-bearing surface of the gills; _b_, stigmata; _c_, spores. Fig. 8. Gills adnate, _i. e._, firmly attached to the stem at their inner extremity, as at _a_. Fig. 9. Cap, with border involute, _i. e._, rolled inward. (See _a_.) Fig. 10. Lamellae or gills dentated or toothed. (See _a_.) Fig. 11. Cap with border revolute, _i. e._, rolled backward. (See _a_.) AGARICINI. Fries. LEUCOSPORI (SPORES WHITE OR YELLOWISH). _Genus Lactarius_ Fries. The plants of this genus have neither veil nor volva. They somewhat resemble the _Russulae_, but can be readily distinguished from them by the greater fleshiness of the stem and by the milky juice which exudes from the flesh. The latter is a characteristic feature of the _Lactars_, giving to the group its name. The species were originally arranged by Fries into groups according to the color and quality of the milk, and of the naked or pruinose character of the gills. Prof. Peck, however, considering the latter character not sufficiently constant or obvious to be satisfactory, in his early reports makes the color of the milk alone the basis of the primary grouping of the American species. Saccardo, in his Sylloge, follows Fries in his classification of the species of the genus Lactarius.