— 6 — 
binomial. The second point suggested by Roll operates again in the direc- 
tion of increasing the existing difficulties, viz. : the fact that his descriptions 
are inadequate. How an incomplete description of a species can be prefer- 
able to a complete one is difficult to see, especially as in this case where the 
descriptions of the component varieties give one often hardly a clue to what 
they stand for. Under the circumstances it is not surprising that while some 
of Roll’s new series of forms contained no distinct species at all, others 
included two or three. Roll’s third point is entirely superfluous, as it is 
already adequately covered by the Vienna rules, while his fourth point 
involves merely the unimportant change that the author’s name now cited in 
parenthesis shall exchange places with the one outside, which, if adopted, 
must of course be accepted for the vegetable kingdom as a whole, not for 
Sphagnum alone. 
By what license Dr. Roll refers to his as the “ new” system in sphag- 
nologyi is difficult to see. It is, viewed in the light of scientific progress, 
antiquated and reactionary in the extreme, I believe it was Limpricht who 
referred to that style of sphagnological nomenclature of which it is the 
extreme representative as “pre-Linnaean”. Warnstorf has in his last 
comprehensive work upon European Sphagnum ^ expressed himself upon 
the absurdity of naming endless varieties and forms, and it is sincerely to 
be hoped that he will in his forthcoming monograph upon the genus act upon 
the courage of his convictions in this respect. There is, be it said, a word of 
truth in Roll’s contention that a species based upon a single specimen, to 
which no subsequently found specimen can be referred, is at best a dubious 
one. This is in principle subscribed to by Warnstorf in his descriptions 
of exotic species, which he expressly states* are tentative and may later upon 
the collection of further material be dissolved into larger specific groups, 
and we may doubtless expect that Herr Warnstorf will in his monograph 
himself undertake the necessary revision. 
Whatever Dr. Roll has contributed to our knowledge of Sphagnum, and 
no one will deny that his observations contain such contributions, he may 
rest assured science will accept with gratitude; it is by no means impossible 
that it may even employ some of his names, but his system in its entirety it 
can certainly not make its own. A ruling that the first variety under each 
of Roll’s new species be considered as its type^ would settle the vexed ques- 
tion as to the validity of certain of his names, notably Sphagmi?n plumu- 
losum; the alternative is to discard his names altogether as non-binomial, 
which is the course pursued by practically all recent bryologists except 
Roth. Ithaca, New York. 
1. Hedwigia 47. pp. 330 f¥. 1908. 
2. Kryptogamenflora der Mark Brandenburg I. pp, 328, 334. 
3. Hedwigia 30, p, 175. 1891, 
