Introduction 



by it. From wherever a toadstool is plucked, it is removed from its 

 mycelium. 



This mycelium is but a thread-like mass of simple cells joined 

 together at their ends and interlacing in a way a thousand-fold more 

 intricate than a Chinese puzzle. Nothing in its structure indicates what 

 its special product will be. The fungus which, is plucked from it is in 

 all its parts simply a mass of these threads cells strung together, in- 

 terlacing and ramifying. 



When the season favors, the mycelium which has, winter and sum- 

 mer and from year to year, lived its hidden life, or has sprung from a 

 germinating spore develops a number of its cells in a minute knob, 

 small as a pin head. At this point the cells make special growth 

 efforts to bring themselves within the favoring influences of heat and 

 moisture; this tiny knob labors within itself, producing cell after cell, 

 which takes shape and function for the future toadstool. 



As it rapidly enlarges it pushes its way toward the surface of the 

 ground, becomes more or less egg-shaped in this stage of its growth, 

 and if cut in half longitudinally and examined, it will display what it is 

 going to be when it grows up. 



Suppose that it belongs to the first of the two great sections into 

 which fungi are divided under the classification of Fries, who modified 

 that of Persoon. The first has the spores which represent the seeds 

 in plants naked, and it is called sporifera or spore-bearing. The sec- 

 ond, which has the spores enclosed in cells or cysts, is called sporidifera 

 or sporidia-bearing. If the cap of a gill-bearing toadstool be laid, gills 

 downward, on a watch crystal or piece of white paper for a few hours, 

 or, in some instances, a few minutes, a complete representation of the 

 spaces between the gills will be found deposited as an impalpable pow- 

 der. These are the spores. 



The first section is divided into four cohorts. Two of these have 

 hymeniums or spore-bearing surfaces more or less expanded. These 

 are Hymenomycetes and Gastromycetes. In Hymenomycetes the 

 hymenium is always exposed in matured plants, as with the common 

 mushroom. When young, some plants are covered with a membrane. 

 In Gastromycetes the hymenium is always concealed within a covering 

 which bursts at maturity, as with the Lycoperdons or puff-balls. Cohort 

 Coniomycetes includes rusts, smuts, etc., formed for the most part on 

 living plants. There is no hymenium present. The spores are produced 



xv 



