Teacher's Leaflet. 



1 109 



The common edible mushroom. (Agaricus compestris), showing button stage, van- 

 ishing ring and gills. 



In studying the stem, its general shape and size in comparison with the cap 

 should be observed; also its color and texture, as brought out by questions. In 

 the common edible species the stem is white and almost cylindrical, tapering slightly 

 toward the base ; and it is solid, although the core is not so firm as the outside. 

 While it has traces of a collar or ring in its earlier stages, these usually dis- 

 appear. This ring or collar, which is very noticeable in many species, is simply 

 the remnant of a membrane called the veil, which during the earlier stages covered 

 the gills and was attached on its outer edge to the rim of the cap and on its inner 

 edge to the stem. As the cap expands, this veil is ruptured and p'art of it may 

 cling to the cap ; the part that clings to the stem is called the ring or annulus, and 

 its form is often a specific character. The common mushroom has this veil so thin 

 that it shrivels and disappears. 



In many species, the young stages — the buttons — are protected by a thick 

 sac or inverted cup-like structure. The young mushroom pushes its cap up through 

 this, breaking it at the top, but it remains a sac or cup about the base of the stem. 

 While there are some edible species which have this sac or "volva," as it is 

 called, inasmuch as the more common deadly species have it the pupils should 

 be taught to avoid eating all mushrooms thus set in cups. Sometimes these cups 

 or sacs fit close to the base of the stem and scale off, and this scaly condition 

 should be looked for as well as the sacs. It should also be impressed on the 

 pupils that absence of this sac does not signify that the mushroom is edible for 

 many poisonous species do not have their stems set in the "death cup." 



The threads or mycelium are the important vegetative organs of mushrooms. 

 They push into the rich soil or decaying wood and gather sustenance and 



