Fig. 219. 



CRYPTOGAMIA. 



living by scraping the rocks of the Scottish Highlands with 

 an iron hoop, for this moss. 



Fig. 218 represents a species of this Fig. 218. 



genus, called Leprous lecanora. It 

 grows in mountains ; crust thin, and 

 leprous white ; seed vessel elevated 

 above the surface, but not on a stalk ; 

 disk plane, olive-colored. 



ORDEJR IX. FUNGI. Mushrooms. 



This order consists mostly of thick fleshy bodies, without 

 herbage, properly so called, and without a thallus. The spo- 

 rules or seeds are arranged in little tubes placed on the infe- 

 rior surface of the pileus or cap. 



The pileus, or cap, is the expanded 

 part of the Mushroom, placed on the 

 upper end of the stipe. The lamella, 

 or gills, consist of thin radiating ex- 

 pansions on the underside of the cap. 

 Among these the sporules are placed. 

 In the young state the cap is globular, 

 and there is a thin membrane or 

 fringe by which its margin is con- 

 nected with the stipe, as in the left hand figure. This is 

 called the volvaor curtain, and as the cap enlarges this bursts, 

 or parts in the direction of the circumference of the pileus, 

 so as to expose the gills. As the plant grows this part be- 

 comes obsolete, and forms the ring around the stipe, called 

 annulus, as shown in the right hand figure. 



It is well known that this tribe of plants spring up almost 

 every where, especially among decaying substances ; and 

 that thousands may be seen in the morning after a thunder 

 storm, and a hot night, where none existed the evening be- 

 fore. Hence some have supposed that these vegetables 

 were fortuitous developments, called into existence by the 

 circumstances of heat, moisture, and peculiarity of soil, and 

 therefore that no seeds were necessary for their production. 

 That the growth or production of these vegetables depends 

 on the circumstances of soil, heat, and moisture, is well 

 known, since the gardeners who raise the esculent Mush- 

 room, in beds constructed for that purpose, have a process 

 so certain, that no other kind is ever known to spring up in 

 these beds, though they may grow every where else in the 



