MUSHROOMS, TOADSTOOLS, AND MOLDS 217 



the under side curious thin vertical plates, called gills or 

 lamella. On these plates the spores develop, falling from 

 them to the ground or being blown away by the winds. 

 The plant has now fulfilled the purpose of its existence, 

 and it rapidly decays a process much hastened by the 

 numerous insect larvae that feed upon the inner tissues of 

 the fungus. 



On most toadstools and mushrooms there may be found 

 a ring of thin tissue with ragged edges, hanging from the 

 upper part of the stem. This is the remnant of a delicate 

 membrane, called the velum, or veil, which covered the 

 surface of the cap during its rapid growth. 



Those species of these fleshy fungi which are not 

 poisonous and are good 

 to eat are called mush- 

 rooms, while the poison- 

 ous ones are commonly 

 called toadstools. No 

 general rule can be given 

 for distinguishing the 

 edible from the poison- 

 ous kinds. 



Perhaps a clearer idea 

 of the relation between MYCELIUM OF THE COMMON MOLD 



the mycelium of a fun- From the spore lying near the middle of the 



gus and its reproductive 



spores may be obtained 



from the picture above 



of one of the common 



molds that grow upon 



bread or other materials in dark, moist situations. The 



branching threads of the mycelium are spread out over a 



wide space. At certain points rise vertical columns. On 



figure, and strongly swollen, one sees the 

 thick threads of the mycelium arise. From 

 the level of the mycelium arise three verti- 

 cal, fertile stalks, a, b, c, of which a is still 

 very young and that at b is already produc- 

 ing a case containing many spores. All 

 highly magnified. 



