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POPULAK SCIENCE REVIEW. 
on the whole the multiplication of genera was uncalled-for 
and unnecessary, and the new genera are constructed on unsound 
principles. 
All the genera in this group (. Ascomycetes ), before the irrup- 
tion of the Groths and Vandals, were constructed on the prin- 
ciple that generic characters should be based fundamentally on 
the vegetative system, leaving the reproductive for specific 
distinction ; that is, differences in the size, form, colour, and 
septation of sporidia, had a primary importance in the discrimi- 
nation of species, but had no generic value. The character of 
the receptacle which contained this fructification had the chief 
place in the generic diagnosis. It was possible under such a 
method at once to refer an immature or an effete specimen to 
its genus, though not to its proper species. The new genera 
are mainly constructed on the basis of the reproductive system, 
and consequently the mature fruit must be known before the 
proper genus can be determined. It is well known that in 
species of Sjohceria which have ultimately sporidia with five 
septa, these sporidia are at first simple ; they then in process of 
development become uniseptate, afterwards triseptate, and 
finally five-septate. There are thus three of the supposed new 
genera through which the same species passes before it arrives 
at its final determination. A specimen found to-day with 
simple spores may be determined as belonging to one genus ; a 
week hence it may be found again with uniseptate sporidia, and 
is then referred to a second genus ; a week or two later, and it 
is met with having triseptate sporidia, and is referred to a third 
genus ; and finally it may be found with five septa to the 
sporidia, and receives still another generic name. This is mani- 
festly playing at science. There is often no internal evidence 
whatever at the different stages that septation will proceed 
further ; and it is only by finding sporidia and asci in different 
stages of development, in the same peridium with the tri- 
septate or quinque-septate sporidia, that the life-history of the 
plant is learnt with certainty. There is another reason why 
this basis of classification is unsound, and that is the very 
different character of the vegetative system, the external habit 
and appearance of different species of Sphceria with very 
similar fruit, not to mention a certain amount of variability in 
the sporidia themselves. Even in the case of coloured sporidia, 
which is often made a chief generic feature, it is well known 
that some species are very long in acquiring their brown colour, 
and may be found ten times with colourless sporidia to once 
with coloured sporidia. Into what difficulty must the student 
be plunged when, instead of finding his Sphceria with hyaline 
sporidia, in a genus so characterised, to be informed that he 
must seek it in one devoted to species with coloured sporidia ! 
