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 (hyphe) which are divided by transverse 
walls formed in regular succession from the end of the 
filament, i.e. the hyphe show a definite apical growth. 
The body of the fungus (mycelium) may be an indefi- 
nite tangled mass of hyphe, 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 hyphe into a firm tissue, such as 
is encountered in the spore-fruits of the large fleshy 
fungi, like the mushrooms, puff-balls, ete. Occasionally, 
as in the large shelf-shaped fungi (Polyporus) and 
many of the so-called “black fungi,” the walls of the 
hyphe 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 
