THE FUNGI 87 



Some of them, it is true, show some resemblance to cer- 

 tain of the Phycomycetes, and may possibly have been 

 derived from them ; but most of the group are so differ- 

 ent that any attempt to determine their origin is little 

 more than pure conjecture. 



These higher fungi are for the most part made up of 

 filaments (hyphse) which are divided by transverse 

 walls formed in regular succession from the end of the 

 filament, i.e. the hyphse show a definite apical growth. 

 The body of the fungus (mycelium) may be an indefi- 

 nite tangled mass of hyphse, or the plant, at least the 

 spore-bearing portion, may have a definite form and firm 

 texture owing to the compact interweaving, and often 

 actual cohesion, of the hyphse into a firm tissue, such as 

 is encountered in the spore-fruits of the large fleshy 

 fungi, like the mushrooms, puff-balls, etc. Occasionally, 

 as in the large shelf-shaped fungi (Polyporus) and 

 many of the so-called "black fungi," the walls of the 

 hyphse become hard and woody in texture. 



The Mycomycetes may be either parasites or sapro- 

 phytes, and occur under a very great variety of condi- 

 tions. Owing to the complete absence of sexual 

 reproduction in many of them, as well as the develop- 

 ment of several very different types of spores, even in 

 the same species, much confusion has arisen in the at- 

 tempts to classify them, as not infrequently the same 

 plant has received several different names based upon 

 different stages of growth. This remarkable polymor- 

 phism has been the cause of endless mistakes in nomen- 

 clature, and at present the classification of the whole 

 group is in a chaotic condition. 



The question of sexuality in the higher fungi has 



