472 



A TEXTBOOK OF BOTANY 



[Ch. X 



or as flecks on the pileus, while a membrane which occurs 

 between the edge of the pileus and the stalk persists as the 

 ruptured velum. On the under side of the pileus develop 

 the gills, i.e. regularly radiating plates of hyphal tissue com- 

 pletely clothed with the hymenium containing the basidia 



Fig. 330. — A Fairy Ring. (Adapted from Bonnier, Le Monde Vegetal.) 



(Fig. 327). On this account the basidiospores fall from 

 the Mushrooms in radiating lines, as can be demonstrated 

 prettily by placing a ripe pileus with the gills downward 

 on dark paper. 



While many of the Agaricineoe are edible (certainly over 



one hundred species in the 



United States), others are 



f ^^^jjk \ very poisonous, as in case 



W^2ff :,filBF of the common Deadly 



Amanita, which has a con- 

 spicuous bright orange-red 

 pileus flecked with white 

 specks (Fig. 329) . No guides 

 exist, except knowledge and 

 experience, for telling the 

 edible from the poisonous 

 species, and many distress- 

 ing accidents have followed 

 amateur attempts to distin- 

 guish them. The poisonous, like the edible, quality seems a 

 mere incident of the metabolism of the plants, and without 

 adaptive significance; and the same appears true as to 



Fig. 331. — Hydn\ 



, pandum; re- 



duced. (From Strasburger.) 



