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 (hyphae) vi^hich 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 hyphee, 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 



