THE BASIDIUM FUNGI (BASIDIOMYCETES) 249 



FIG. 203. Gills of a 

 toadstool 



On the faces of the gills 

 the spores are formed. 

 Seven and one-half times 

 natural size. After Buller 



end of the stalk (stipe) (Fig. 202). As the pileus opens, it is 



joined to the stalk beneath by means of a layer of hyphae (the 

 veil). This in some species, in breaking 

 away from the pileus, 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 point of attachment to 

 the stalk. The flat surfaces of the adja- 

 cent plates face one another (Fig. 203). 

 Some of the hyphse which compose the 

 gills grow in such' a way that their tips 

 extend a little way from the surface of 

 the gill. Upon this extended tip (ba- 

 sidium) four (rarely two) branches are 

 formed, and upon the tip of each branch 

 a spore (lasidiospore) is formed (Fig. 

 204). When the spores fall upon moist, 



warm, nutrient material, they produce a new mycelium. By 



Cutting the pileus of a ripe toadstool from the stalk and placing 



it with the gills downward upon 



a piece of ordinary white or black 



paper, after a few hours there will 



be made a "spore print" composed 



of thousands of spores. 



237. Toadstools and mushrooms: 



different forms and habits. The type 



form just described is representa- 

 tive of the most common toadstools 



and mushrooms. The commonest 



cultivated mushroom (Agaricus cam- 



pestris) has long been a well-known 



article of food. Some of the same 



type of toadstools form "fairy rings" (Figs. 205 and 206), 



which in constantly widening circles may appear in the same 



locality year after year. The phenomenon is doubtless due 



FIG. 204. Basidia and spores 

 of a toadstool 



Three hundred seventy times 

 natural size. After Buller 



