22 FETCH : REVISIONS OF 



are far more abundant in the Tropics than in other regions. 

 "The genera characterized by a tough, leathery pileus that 

 dries up and becomes rigid and persistent are more numerous 

 in the tropics than the fleshy putrescent genera " (Massee). 

 " The fleshy Hymenomycetal fungi belong almost exclusively 

 to temperate regions : as warmer countries are approached, 

 they are only found at high elevations, whilst their represen- 

 tatives near the sea level belong to genera in which the sub- 

 stance is tough and leathery, and the projiortion of water in 

 their composition is comparatively small. Hence we find that 

 nearly all the fungi of the agaric type to be met with constantly 

 in the Tropics belong to such genera as Marasmius , Schizo- 

 phyllum, Lentinus, and the almost woody Lenzites " (Cooke). 

 But it by no means follows that this is actually the case. 

 The preponderance of these fungi in existing collections is 

 merely an accident of collection. If we take Berkeley and 

 Broome's account of the fungi of Ceylon, we find that, among 

 the basidiomycetes, the number of species which readily decay 

 exceeds that of the tough or woody species which can be easily 

 dried and preserved ; and it is highly probable that this will be 

 found to be true of other countries also. When the question 

 is considered on the spot, it does not seem probable that the 

 Polypori and Lentini should outnumber the putrescent agarics : 

 the evanescent fructification of the latter is far better adapted 

 for the propagation of the species than the tough and woody 

 sporophores of the Polypori, which are subject to the attacks 

 of innumerable insects during their comparatively prolonged 

 period of exposure, though this is much shorter than in tem- 

 perate climates. It is rare to find Fomes showing its " annual " 

 growths : the sporophore does not last long enough. Very 

 frequentlj^ also the sporophore never reaches maturity, but 

 stops growing when the rain suddenly ceases , and is then eaten 

 by insects. The idea that the leathery hymenomycetes are 

 the more fitted for a tropical climate ignores such questions 

 as humidity and rainfall, and the existence of the essentially 

 tropical genera, Gleoporus and Laschia. 



