414 ALFRED W. BENNETT AND GEORGE MURRAY. 
by the abandonment of a large number that are absolutely 
useless. 
So far as we know^ the first systematic attempt at placing 
cryptogamic terminology on a more satisfactory footing was 
made by Sachs in the fourth edition of his ^ Lehrbuch ^ (not 
yet published in English), which is deserving of commenda- 
tion, though it does not appear to us altogether successful. 
Sachs proposes (p. 243) to define a spore ” as a reproduc- 
tive cell produced directly or indirectly by an act of fertili- 
sation,^’ reserving the term gonidium ” for those repro- 
ductive cells which are produced without any previous act 
of impregnation. As far as Vascular Cryptogams and Mus- 
cineee are concerned, Sachs’s proposal involves no change, 
since he regards the spores, which are a part of the non- 
sexual generation, as the indirect result of the act of fertili- 
sation which closes the sexual generation. In the Basi- 
diomycetes he is able to retain the term spore for the 
familiar bodies commonly so called, only by the assumption 
— for at present it is nothing more — that the structure of 
which the hymeniurn forms a part is the result of a 
yet undiscovered process of fertilisation on the mycelium. 
In the lower fungi the changes involved in the proposal 
are considerable. Thus the spores ” of Penicillium, 
similar as they are to those of Agaricus, can no longer be 
called spores, because they do not result from an act of ferti- 
lisation, but become conidia ” or gonidia and for the 
same reason the familiar zoospores ” of the lower Thallo- 
phytes become zoogonidia.” It is obvious that one practical 
defect of this suggestion is that it may necessitate a per- 
petual change of terminology as our knowledge advances. 
Every fresh extension of the domain of sexual fecundation— 
and it is probable that many such will take place — wfill 
involve the removal of a fresh series of reproductive cells 
from the category of gonidia to that of spores, even though 
they may not be the immediate result of an act of fertilisa- 
tion. Again, if the spores of Ferns and Mosses are the 
indirect result of impreguation, it is difficult to say why the 
term should not ultimately include all reproductive bodies 
whatever, except the spores of the apogamous ferns ” with 
which Earlow and De Bary have recently made us ac- 
quainted, and of other similar abnormal productions, which 
are certainly not the result of impregnation, direct or in- 
direct. 
It seems a sounder principle — and is certainly more con- 
venient to the student — to base a system of terminology on 
facts which can be confirmed by actual observation, rather 
