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!LVANE, 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. 



