274 FUNGI. 



temperate and frigid zones for their special abode, and some of 

 them at times find their way to the higher regions of the Alps. 

 No one can describe the luxuriance of the torrid zone in Poly- 

 pori and Trametes, genera of Hymenomycetes, which flourish 

 beneath the shade of the virgin forests, where perpetual moisture 

 and heat promote their vegetation and give rise to an infinite 

 variety of forms. But though the genus Poli/porus, which rivals 

 Ayaricus in the number of its species, inhabits, in preference, 

 warm climates at large, it nevertheless exhibits species peculiar 

 to each country. This arises from the circumstance that the 

 Potypori, for the most part, live upon trees, and are dependent 

 on this or that particular tree for a suitable habitat ; and the 

 tropical flora being prolific in trees of all kinds, a multitude of 

 the most varied forms of these fungi is a necessary consequence. 

 Hexagona, Favolus, and LascTiia are common in inter-tropical 

 countries, but they are either entirely absent or extremely rare 

 in temperate climes. 



When the majority of the species of a genus are of a fleshy 

 consistence, it may generally be concluded that that genus 

 belongs to a Northern region, even if it should have some repre- 

 sentatives in lands which enjoy more sunshine. Thus the Hydna 

 are the principal ornaments of Northern forests, where they attain 

 so luxuriant a growth and beauty that every other country must 

 yield the palm to Sweden in respect to them. In an allied genus, 

 that of Irpex, the texture assumes a coriaceous consistence, and 

 we find its species to be more especially inhabitants of warm 

 climates. 



Most of the genera of Auricularini are cosmopolitan, and the 

 same is true of some species of Sfcreum, of Corticium, etc., which 

 are met with in countries of the most different geographical 

 position. In tropical countries, these genera of fungi assume the 

 most curious and luxuriant forms. The single and not consider- 

 able genus Cypliellfi appears to be pretty uniformly distributed 

 over the globe. The Olavaricei are equally universal in their 

 diffusion, although more plentiful in the norjth; however, the 

 penus Pterula possesses several exotic forms, though in Europe 

 it has but two representative species. That beautiful genus of 



