Band 107. Nr. 10. 
XXIX. Jahrgang. I. Bd. Nr. 10. 
Botanisches Oentralblatt. 
Referirendes Organ 
der 
Association Internationale des Botanistes 
für das Gesamtgebiet der Botanik. 
Herausgegeben unter der Leitung 
des Präsidenten: des Vice-Präsidenten: des Secretärs. 
Prof. Dr. R. v. Wettstein. Prof. Dr. Ch. Flahault. Dr. J. P. Lotsy. 
und der Redactions-Commissions-Mitglieder: 
Prof. Dr. Wm. Trelease, Dr. R. Pampanini und Prof. Dr. F. W. Oliver. 
von zahlreichen Specialredacteuren in den verschiedenen Ländern. 
Dr. J. P. Lotsy, Chefredacteur. 
Abonnement für das halbe Jahr 14 Mark 
* durch alle Buchhandlungen und Postanstalten. BKJb. 
Alle für die Redaction bestimmten Sendungen sind zu richten an Herrn 
Dr. J. P. LOTSY, Chefredacteur, Leiden (Holland), Witte Singel 26. 
Willis, J. C., Some Evidence against the Theory of the 
Origin of Species by Natural Selection of Infinitesimal 
Variations, and in favour of Origin by Mutation. (Annals 
of the Royal Botanic Gardens Peradeniya. Vol. IV. p. 1 — 15. 
May, 1907.) 
The author revives the familiär argument that specific differences 
are generally useless, and therefore cannot have arisen through the 
action of Natural Selection. To this argument it has been replied 
that any given character may be useful under unknown circumstan- 
ces and in places not specified. The author considers this repl} r not 
to be valid in the case of the endemic species with which he deals, 
notably in the case of Coleus elongatus Trimen, a species confined 
to the summit of Ritigala — an isolated mountain in Ceylon. In 
the same locality and Situation are found specimens of the widely 
distributed C. barbatus, which is stated to be the nearest allv of 
C. elongatus but to differ from it in several marked features. Assu- 
ming that C. elongatus is descended from C. barbatus, a conclusion 
which the author regards as inevitable from its distribution and 
other considerations, if this change was due to the selection of 
minute variations, the points in which the former species differs 
should have some use in their present locality where the species 
must be supposed to have originated. None of the differences howe- 
ver appear to be of any use. 
Refering to the Ceylon endemics in general they are described 
as “a group of some 800 species of which about two-thirds or more 
are rare, confined to one or a very few localities.” In particular they 
Botan. Centralblatt. Band 107. 190S. 16 
