FLOWERLESS PLANTS 447 



carried by air currents. Thus they form a constituent of 

 dust. If the gills or tubes of a mushroom are dark colored, 

 we will make the spore print on white paper, if white, on 

 black paper, and if we care to keep the spore prints, we 

 will use paper over which a thin coating of mucilage has 

 been laid. This may be allowed to dry, as the moisture 

 in the spores will cause them to stick to it. 



The food value of mushrooms has been exaggerated by 

 popular writers. Chemical analyses have shown that they 

 are about as nutritious as cabbage. Rated at twenty-five 

 cents a pound, which is from one-fourth to one-tenth the 

 usual price, they cost about ten times as much for actual 

 nutrition obtained as beef at fifteen cents per pound and 

 1 24 times as much as wheat flour at two and one-half 

 cents a pound. However, they afford variety ; a few species 

 are said to be ''delicious," and a very few are poisonous. 

 As a people we are behind most European nations in 

 knowledge of mushrooms and, hence, in ability to utilize 

 them for food. The main reason for introducing their 

 study into nature-study courses is to give definite instruc- 

 tion, first, about the few poisonous species and, second, to 

 point out a number of the more valuable kinds that now 

 go to waste in large quantities in our woods and pastures 

 and even city lawns and gardens. To do this adequately 

 would require a book, but a few points of general impor- 

 tance may be given in connection with the following partial 

 outline of their classification. 



Since the conspicuous part of a mushroom is a mechanism 

 for producing and disseminating the spores, they are natu- 

 rally classified by the position and form of the spore-bearing 

 surfaces or parts. 



