8 FUNGI. 
permeate the tissues of plants attacked by parasitic fungi, or 
they run over dead leaves forming whitened patches, formerly 
bearing the name of Himantia, but really the mycelium of some 
species of Alarasmius. If checked or disturbed, the process 
stops here, and only a mycelium of interwoven threads is 
produced. In this condition the mycelium of one species so: 
much resembles that of another, that no accurate determination 
can be made. If the process goes on, this mycelium gives rise 
to the stem and cap of an agaricoid fungus, completing the 
vegetative system. This in turn gives origin to a spore-bearing 
surface, and ultimately the fruit is formed, and then the fungus 
is complete ; no fungus can be regarded as perfect or complete 
without its reproductive system being developed. In some this is 
very simple, in others it is as complex. In many of the moulds we 
have miniature representatives of higher plants in the mycelium 
or roots, stem, branches, and at length capsules bearing sporidia, 
which correspond to seeds. It is true that leaves are absent, 
but these are sometimes compensated by lateral processes or 
abortive branchlets. A tuft of mould is in miniature a forest of 
trees. Although such a definition may be deemed more poetic 
than accurate, more figurative than literal, yet few could believe 
in the marvellous beauty of a tuft of mould if they never saw it 
as exhibited under the microscope. In sucha condition no doubt 
could be entertained of its vegetable character. But there is a 
lower phase in which these plants are sometimes encountered ; 
they may consist only of single cells, or strings of cells, or threads 
of simple structure floating in fluids. In such conditions only 
the vegetative system is probably developed, and that imperfectly, 
yet some have ventured to give names to isolated cells, or 
strings of cells, or threads of mycelium, which really in them- 
selves possess none of the elements of correct classification—the 
vegetative system, even, being imperfect, and consequently the 
reproductive is absent. As already observed, no fungus is per- 
fect: without fruit of some kind, and the peculiarities of structure 
and development of fruit form one of the most important elements 
in classification. To attempt, therefore, to give names to such 
imperfect fragments of undeveloped plants is almost as absurd 
