202 CIVIC BIOLOGY 



for from six to twelve hours, then its iron grip holds to the death. For 

 centuries it has defied all remedies. MC!LVANK, p. 5 



The amanitas are the most conspicuous, beautiful, and, too 

 often, the most abundant mushrooms to be found in the woods 

 from frost to frost. Of the twenty-eight species nine are 

 deadly, ten are doubtful, and nine are considered edible. 



The three characters which infallibly mark an amanita are 

 white spores, a ring, and a volva, or cup. In order to understand 

 these terms and others that we need to know, study an amanita 

 as a type. Fig. 98 shows all the constituent parts and all the 

 characteristic stages of growth of Amanita phalloides. 



The parts in order of growth and formation are 



MYCELIUM : extremely fine white threads, uniting here and there to 

 form larger strands the nutritive, or vegetative, part of the 

 fungus. 



BUTTONS : white knots or balls in the mycelium, the beginnings of 



spore-forming bodies (mushrooms). One button cut lengthwise 



. shows the parts, which will be more clearly differentiated later 



on. Note especially that the mushroom proper at this stage is 



completely enveloped in a sac. Not all mushrooms have this sac. 



SPOROPHORE, consisting of 



1. Stem : the part which springs directly out of the mycelium 



and supports the pileus. 



2. Pileus, or Cap : the umbrella-shaped part which carries, on its 



under surface, radiating, leaf-like structures the gills. 



3. Gills : the organs from the surfaces of which the spores are set 



free. The shape that the spore-forming surface assumes is a 

 prime character in classification. It is produced into gills in 

 the Ayaricacece, into spines in the Hydnacece, into tubes in 

 the Boleti, and into fine pores in the Polypori. 



SPORES : Place a cap from which the stem has been removed, gills 

 down, on a piece of white or black paper, and cover tightly with 

 a tumbler or bell jar. Leave for an hour or so, and examine the 

 spore print and, if a microscope is available, the spores. 

 VOLVA, or SAC : the membranous sac which may envelop the entire 

 sporophore in the button stage ; also applied to the portion 

 which, after rupture, remains as the cup at the base of the stem. 



