TOADSTOOL OR MUSHROOM. 61 



ANNOTATIONS. 



The Basidiomycetes, to which the toadstools, mush- 

 rooms, and puffballs belong, are probably the most con- 

 spicuous representatives of the Fungi. Some of the 

 forms are saprophytic and others are parasitic in their 

 way of living. It is customary in the entire group to 

 have most of the mycelium growing within the substance 

 which furnishes food, and to have the organs for spore 

 formation developed aerially. The main body of the 

 structure ordinarily called the toadstool is made up of a 

 mass of hyphal threads. Some of these threads pass 

 through the stalk and into the gills, and terminate in 

 club-like expansions which extend outward from the 

 surface of the gill. From these club-like expansions, 

 the basidia, there arise small tapering branches whose 

 tips gradually enlarge until a spherical body is formed, 

 which finally becomes a spore. In some species four 

 and in others two such spores are formed. To indicate 

 the peculiar way in which it is formed this is called a 

 basidiospore. The spores are usually distributed by 

 the wind, though a variety of agencies may be used. 

 They germinate, and if in favorable location develop 

 a new mycelium and eventually a new toadstool. 1 



1 Examine texts to discover the prevailing opinions regarding ho- 

 mologies between the basidium and the sporangium. 



