veil wliicli stretches across from the stem to tlie inarf^in of the 

 cap. These young- phaiits are called "button iun.shrM()m.s." As 

 the phiut <h-velupd and the ca}) expands, the edge of the veil sepa- 

 rates from the margin of the cap, but still adheres to the stem, 

 and forms the ring or collar. The eaj), when fully expanded, is 

 broadly convex, or nearly flat above. It is generally adorned 

 ■with silky fibrils, but sometimes these arc collected in such a way 

 as to form little bundles or scales, which, however, arc usually 

 scarcely noticeable. In old age they liave often vanished, and 

 the cap appears quite smooth. Its margin generally extends 

 slightly beyond the outer extremity of the gills. 



The color of the cap varies from pure white to ])rown or 

 tnwnv brown. The flesh is white. The gills, when first revealed 

 by the separation of the veil, are of a delicate pale pink hue, but 

 with advancing age this gradually deepens, and finally turas to 

 a dark brown or blackish-brown color. In dried specimens the 

 color might easily be called black. 



The stem is rather short — scarcely as long as the cap is broad. 

 It is nearly cylindrieal, i. e., about as thick at the top as at the 

 bottom, and its color is white or whitish. The substance in the 

 centre is a little softer or more spongy than toward the exterior, 

 and for this reason the stem is descriljed as "stuffed," as if it were 

 filled with a pith. Sometimes the collar shrivels so much that it 

 is scarcely perceptible in old plants, or it may even disappear en- 

 tirely. The s})ores are brown in the mass. They are sometimes 

 described as purplish-brown, but I never could detect any pur- 

 plish tint in them or in the gills. 



This mushroom, like many other plants that have been long 

 and extensively cultivated, has developed into several varieties, 

 whieli exhibit quite well marked distinctive features. 



The AYhite variety, var. alhus, has the cap and stem white, the 

 ca]> silky and the stem short. This is our most common wild 

 form, and it is also cultivate I. 



The Gray variety, var. griseus, has the cap gray, silky and 

 shining. T ha^'o seen this from Virginia only. 



The Garden variety, var. hortensis, has the cap brownish, or 

 almost tawnv brown, and fibrillose, or marked with obscure 

 scales. This variety is often cidtivated, but rarely found Avild. 



Several other varieties are recorded as European, but I have 

 seen none of them in this country. 



Generally the cap of the Common mushroom is two to four 

 inches broad, the stem one to three inches long, and one-third to 

 two-thirds of an inch thick. Its most frequent place of growth is 



27 



