tuberculate or irregular, simple or composite, transparent or nebulous, etc.

Jules Bel, 5 groups: White; pink; red; brown; black.

Dr. Gautier, 5 shades: White; pink; brown; purplish-brown; black.

Constantin & Dufour, 5 groups: White; pink; ochraceous; brownish-purple; black.

J. P. Barla, 7 groups: Leucosporii, white; Hyporhodii, pink; Cortinariæ, ochraceous; Dermini, rust; Pratellæ, purplish-black; Coprinarii, blackish; Coprini and Gomphi, dense black.

L. Boyer, 5 groups, 11 shades: White to cream yellow; pale pink to ochraceous yellow; bay or red brown to brown or blackish bister; rust color, cinnamon or light yellow.

W. D. Hay, 5 groups: White; pink; brown; purple; black.

C. H. Peck, 5 groups: Leucosporii, white; Hyporhodii, salmon; Dermini, rust; Pratellæ, brown; Coprinarii, black.

Saccardo divides the Agaricini into four sections, according to the color of their spores, as follows: Spores brown, purplish brown or black, Melanosporæ; spores ochraceous or rusty ochraceous, Ochrosporæ; spores rosy or pinkish, Rhodosporæ; spores white, whitish or pale yellow, Leucosporæ.

Dr. M. C. Cooke, 5 groups: Leucospori, white or yellowish; Hyporhodii, rosy or salmon color; Dermini, brown, sometimes reddish or yellowish brown; Pratellæ, purple, sometimes brownish purple, dark purple, or dark brown; Coprinarii, black or nearly so.

These shades are somewhat different from the colors of the mushrooms' gills, so that, when it is of importance to determine exactly the color of the spore in the identification of a species, we may without recourse to the microscope cut off the stem of an adult plant on a level with the gills and place the under surface of the cap upon a leaf of white paper if a dark-spored species, and upon a sheet of black paper if the spores are light. At the expiration of a few hours we will find, on lifting the cap, a bed of the shed spores which will represent their exact shade. These may be removed to a glass slide and their size and form determined by means of the microscope.

In the present work Dr. M. C. Cooke's grouping of the spore series is adopted.