The three mushrooms illustrated and described in this pamphlet, Plates I, II, and III, are of the order Agaricini or gilled mushrooms. They are well-defined types and of wide geographical distribution. FOOD VALUE OF MUSHROOMS. Rollrausch and Siegel, who claim to have made exhaustive investigations into the food values of mushrooms, state that "many species deserve to be placed beside meat as sources of nitrogenous nutriment," and their analysis, if correct, fully bears out the statement. They find in 100 parts of dried _Morchella esculenta_ 35.18 per cent. of protein; in _Helvella esculenta_, 26.31 per cent. of protein, from 46 to 49 per cent. of potassium salts and phosphoric acid, 2.3 per cent. of fatty matter, and a considerable quantity of sugar. The _Boletus edulis_ they represent as containing in 100 parts of the dried substance 22.82 per cent. of protein. The nitrogenous values of different foods as compared with the mushroom are stated as follows: "Protein substances calculated for 100 parts of bread, 8.03; of oatmeal, 9.74; of barley bread, 6.39; of leguminous fruits, 27.05; of potatoes, 4.85; of mushrooms, 33.0." According to Schlossberger and Depping, in 100 grams of dried mushrooms they found the following proportions of nitrogenous substances: -----------------------+-------- Varieties. | Grains. | Chanterelles | 3.22 Certain Russulas | 4.25 Lactarius deliciosus | 4.68 Boletus edulis | 4.25 Meadow mushroom | 7.26 -----------------------+-------- But all chemists are not agreed as to these proportions. For instance, Lefort has found 3.51 grains of nitrogenous matter in the cap of _Agaricus campestris_, 2.1 grains in the gills and only 0.34 of a grain in the stem. Payen has found 4.68 grains in _Agaricus campestris_, 4.4 grains in the common Morel (_Morchella esculenta_), 9.96 grains in the white truffle, and 8.76 grains in the black.