SUPPLEMENT 



organic food. The delicate cells of the fungus mycelium absorb food 

 very rapidly, the food material being mainly atmospheric moisture 

 and the salts and gases dissolved therein, but the hyphae that pene- 

 trate the substratum do select and appropriate from it some food 

 materials, which they dissolve by means of an excretion. Lichens, 

 like many other lower plants, and like liverworts and mosses in a 

 higher group, have the power of surviving long periods of dessication 

 and reviving with marvelous rapidity. 



Children are sure to be interested in toadstools, and there is no 

 difficulty in getting a collection of them after a heavy rain. Urge 

 the children to hunt for the part that absorbs the food, the mycelium. 

 It is sometimes almost invisible, the delicate filaments or hyphse being 

 obscured by the soil. When the mycelium must thread its way through 

 loose, decaying leaves, it is sometimes a webby mass of considerable 

 extent, but usually the vegetative part is absurdly small as compared 

 with the spore-be? ring part. The rapidity of the growth of the spore- 

 fruit is simply inexplicable. We may bear in mind that rich, ready- 

 made food is at hand, and that the long, slender, thin-walled cells of 

 a fungus mycelium always have the power of rapid absorption, or that 

 the mycelium may have been at work for a long time before sending 

 up the spore-fruit, still the cell-making energy that results in the for- 

 mation of a compact body as large as an egg from a minute, vegetative 

 part in a few hours, is marvelous. 



The collection of toadstools is pretty sure to include the one most 

 commonly eaten, Agaricus campestris, and this species shows very 

 prettily the different stages of growth of the cap or spore-bearing 

 part. The little white nodules early show the beginnings of gills 

 within ; then there is the stage where the veil, or volva, which has 

 protected the gills, is beginning to break from the stalk. Have the 

 children notice that in this species, the remains of the volva always 

 form a ring well up on the stem. In the poisonous Amanita, No. 2, 

 the broken volva is left at the base of the stalk forming a little cup. 

 As the cap of the Agaricus expands, it can be seen that the gills are 

 unequal in length ; they are at first a delicate flesh color, but they 

 become darker as the spores mature, the ripe spores being nearly 

 black. 



The collection will also probably contain some of the Coprinus 

 group, toadstools whose caps do not fully expand and that 

 liquify when the spores are mature. The large one, No. 3, in the 

 picture, is a delicate grey and pink species ; small light-brown Coprini 

 are more common. Sometimes members of this group have a 

 rather foetid odor that is useful in attracting carrion beetles, and flies. 



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