CRYPTOGAMS 323 



D. Mushrooms 



Material. — Any kind of gilled mushroom in different stages of de- 

 velopment, with a portion of the substratum on which it grows, contain- 

 ing some of the so-called spawn. The common mushroom sold in the 

 markets {Agaricus campestris) can usually be obtained without difficulty. 

 Full directions for cultivating this fungus are given in Bulletin 53 of the 

 U. S. Department of Agriculture. From 6 to 12 hours before the lesson 

 is to begin, cut the stem from the cap of a mature specimen, close up to 

 the gills, lay it, gills doAvnward, on a piece of clean paper, cover with a bowl 

 or pan to keep the spores from being blown about by the wind, and leave 

 until a print (Fig. 466) has been formed. 



367. Mushrooms and toadstools. — The popular distinc- 

 tion which limits the term " mushroom " to a single species, 

 the Agaricus campestris, and classes all others as toadstools, 

 has no sanction in botany. All mushrooms are toadstools 

 and all toadstools are mushrooms, whether poisonous or 

 edible. The real distinction is between mushrooms and 

 puffballs, the former term being more properly applied to 

 fungi which have the spore-bearing surface exposed. 



368. Examination of a typical specimen. — The most 

 highly specialized of the fungi, and the easiest to observe on 

 account of their size and abundance, are the mushrooms 

 that are such familiar objects after every summer shower. 

 The gilled kind — those with the rayed laminae under the 

 cap — are usually the most easily obtained. Specimens 

 should be examined as soon after gathering as possible, since 

 they decay very quickly. 



369. The mycelium. — Examine some of the white fibrous 

 substance usually called spawn through a lens. Notice 

 that it is made up of fine white threads interlacing with each 

 other, and often forming webby mats that ramify to a con- 

 siderable distance through the substratum of rotten wood 

 or other material upon which the fungus grows. This webby 

 structure, often mistaken for root fibers, is the thallus or 

 true vegetative body of the plant, the part rising above 

 ground, and usually regarded as the mushroom, being only 

 the fruit, or reproductive organ. Place some of the mycelium 



