[Chap. XLIV 



THE FUNGI 



555 



Mushrooms, toadstools, and puffballs. These are popular terms and do 

 not correspond to any technical classification of fungi. To many people 

 the term "mushroom" means an edible fungus while "toadstool" refers 

 to a poisonous or inedible one. No such distinctions can be made on the 

 basis of the form, color, structure, or place where they grow. A few 

 species may be safely eaten by some persons, but not by others. Beside 

 the edible species, others are woody or unpalatable, and a number of 

 species are deadly poisonous to everyone. The temi "puffball" refers to 

 a fungus that emits clouds of spores when stepped on. Puffballs are 

 inedible when mature, but many of them are edible when young. Per- 

 haps the best advice to would-be mushroom hunters is to learn to identifv 

 positively a few of the common edible species and avoid all others. 



The vegetative parts of all these fungi are in the soil, wood, or other 

 substrate on which the fruiting bodies appear. The fruiting bodies are 

 compact masses of hyphae, varying from a fraction of an inch to two 

 feet or more in height, or diameter. When mature, the reproductive 

 structures may contain countless numbers of spores. The spores of toad- 

 stools develop in groups of four from the ends of short club-shaped 

 hyphae, called basidia, which in turn develop on the sides of gills, tubes, 

 or spine-like projections on the lower side of the cap of the toadstools 

 (Figs. 245 and 246). 



h^^' ■' "C.'^:"'.C^£&-- ■ f K 



Fig. 246. Arrangement of spores on the gills of the cultivated mushroom: at 

 the left a vertical section of one gill as it appears when magnified enough for one 

 to see the continuous external layer of basidia; on the right a highly magnified sec- 

 tion of a small portion of a gill including several basidia, three of which have 

 2 basidiospores. In the wild species of this mushroom each basidium bears 4 

 basidiospores. Modified from J. Sachs. 



