The Evolution of Species in Ceylon, with reference to 
the Dying Out of Species. 
BY 
J. C. WILLIS, M.A., Sc.D. 
With two Figures in the Text. 
I N a paper recently published 1 I have brought forward conclusions 
which have such far-reaching bearings upon many branches of botany 
(and probably of zoology also) that it will be well to re-enunciate them 
in connexion with the further deduction here made from the figures, and 
which was briefly indicated in that paper, that there is little evidence to 
show that any species of Angiosperms are dying out. 
In a recent paper 2 upon the Podostemaceae and Tristichaceae I have 
endeavoured to show that these families, living as they do (and must 
always have done) under perfectly uniform conditions, cannot owe their 
evolution to Natural Selection. At the same time they show wide and 
extraordinary distinctions between species and genera, of the ordinary 
‘ Linnean ’ type. 
In a further paper 3 on the origin of these families I have endeavoured 
to show that they must have arisen from land plants growing at the sides 
of the streams, and in any case that the first change necessary to give rise 
to their ancestral forms must have been a ‘ large ’ change, which could not 
therefore have been due to Natural Selection. 
In a series of papers published in Ceylon 4 from 1906 to 1911 I have 
devoted attention to the very interesting endemic species of that island, 
and have endeavoured to show that they cannot be regarded as local 
species owing their origin to the operation of Natural Selection in response 
to local needs or conditions. These endemic species are not a casual 
1 The Endemic Flora of Ceylon, with reference to Geographical Distribution and Evolution in 
general. Phil. Trans., B, vol. ccvi, 1915, p. 307. 
2 On the Lack of Adaptation in the Tristichaceae and Podostemaceae. Proc. Roy. Soc., B, 
vol. lxxxvii, 1914, p. 532. 
3 The Origin of the Tristichaceae and Podostemaceae. Ann. of Bot., vol. xxix, 1915, p. 299. 
4 Six papers in Ann. Perad., vols. iii-v, 1906-11. 
[Annals of Botany, Vol. XXX. No. CXVII. January, 1916.] 
