so 
Modern mycology. 
respectively influenced the study of systematic mycology some- 
what as follows : — 
(1.) The large sections of fungi known as the Pyrenomycetes 
and the Hypliomycetes were — when recognized at all by the old 
authors— classified according to naked eye, or, at the most, 
pocket lens characters. It has been shown in hundreds of 
instances, where external characters alone did not suggest a 
specific difference between two given organisms, that the com- 
pound microscope has clearly demonstrated differences which are 
accepted at the present day as being of generic or even ordinal 
value, and thousands of species belonging to the above-mentioned 
and other groups, coming under the category of micro-fungi, have 
been added during the last thirty years, resulting entirely from the 
modern perfection of the microscope. As would be expected, all 
this array of modern species are not equally good, and the abuse — 
as we consider — in the use of the microscope in connection with 
the tremendous increase of species will be considered at a later 
stage. 
(2.) The attention paid to fungi by botanical collectors in 
almost every part of the world during late years has added 
materially to the number of previously known species. At the 
same time, it is perfectly certain that hundreds of species founded 
on dried specimens, too often received without a word of informa- 
tion qs to habitat, structure, colour, etc., will never be recognized 
again from the necessarily meagre descriptions given, and hence 
will arise a duplication of names, the same species being received 
a second time under more favourable conditions as to preservation, 
accompanying information, etc., being found to present characters 
differing from any known form, will be described as a new species. 
This difficulty could be completely overcome by not founding 
species on imperfect material, but, apparently, all who have to deal 
with exotic collections received in a dry state do this to some 
extent, hence, in place of recrimination, the thing that suggests 
itself is — don’t do it again. 
(3.) So long as a specific diagnosis does not contain an absolute 
error, perfect and imperfect appear to be relative terms, depending 
entirely on personal opinion ; and brevity being considered by the 
great majority as a cardinal virtue, factors that are looked upon as 
being of minor importance are not unfrequently entirely omitted 
from a diagnosis. It not unfrequently happens that the one or 
more features considered as of prime importance by one person or 
clique are almost entirely ignored by the followers of a second 
system, and vice versa ; hence crops up a grave difficulty, each 
party is endeavouring to understand the species of the other by the 
use of one or more characters in the value of which, comparatively 
speaking, no confidence is placed. As an illustration of the above, 
the Friesian school of mycologists consider that for the correct 
identification of a species of Agaricus a detailed account of pileus, 
gills, and stems is necessary, the weak point— until quite recently 
