MUSHROOMS AND TOADSTOOLS 



247 



fruit body arises which has a peridium of two or three layers. The 

 outer peridium is leathery and tough, while the inner peridium is gelat- 

 inous at maturity. The outer peridium remains at the base, as a 

 cup called the volva. The sporophore, pileus, or cap, is raised up on the 

 end of a stalk, or stipe, which is usually spongy in character. The 

 sporophore takes a variety of forms, but in all cases, its outer surface at 



J 3 ■ 



Fig. 98. — Clathrus canccllaius, fully mature fruit-body, natural size. (After Ed. 

 Fischer, Die naliirlichen Pjianzenfamilien I. lA**. p. 282.) 



first represents the hymenium which deliquesces at maturity, so that the 

 minute spores are imbedded in a greenish, fetid slime, which gives off a 

 penetrating, nauseating odor, attractive to blue-bottle flies, that lick 

 off the malodorous slime with evident enjoyment and are the agents 

 by which the spores are distributed. In fact, it has been proved that 

 the basidiospores germinate better after passage through the alimentary 



