258 



INTRODUCTION TO BOTANY 



to the stalk beneath by means of a layer of liyphse (the veil). 

 In some species, when the veil breaks away from the pileus, 

 it forms a ring, or annulus, about the stalk. 



The underside of the pileus is made up of plate-like growths 

 (gills) which radiate from the stalk. Some of the hyphae 

 which compose the gills extend from the surface of the gill, 



FIG. 200. A poisonous fungus (Amanita muscaria) 

 From A. H. R. Buller's " Researches on Fungi " 



and upon this extended tip (the basidium, or stalk) four 

 (rarely two) branches are formed. Upon the tip of each 

 branch a spore (basidiospore) is formed (fig. 201). When the 

 spores fall upon moist, warm, nutrient material, they produce 

 a new mycelium. If the pileus of a ripe mushroom is cut from 

 the stalk and placed, with the gills downward, upon a piece of 

 ordinary white or blank paper, after a few hours a spore print 

 composed of thousands of spores will be made. 



