Studies on the Evolution of the Angiosperms. 
The Relationship of the Angiosperms to the Gnetales. 
BY 
E. A. NEWELL ARBER, M.A, F.L.S , F.G.S., 
Trinity College , Cambridge ; University Demonstrator in Talaeobotany. 
AND 
JOHN PARKIN, M.A., F.L.S., 
Trinity College , Cambridge . 
With three Figures in the Text. 
I N a former paper 1 we, conjointly, gave a sketch of the main conclusions 
respecting the ancestry of the Angiosperms, at which we had arrived 
after some years’ study of the subject. The kind reception 2 extended 
to our endeavours to construct a working hypothesis, however imperfect, 
towards the solution of the problem, has encouraged us to pursue the matter 
further. We thus propose to elaborate certain questions which, in our pre- 
liminary paper, were purposely passed over or only treated summarily. 
These further studies we hope to publish from time to time, either con- 
jointly or separately, in a series of which the present forms the first 
instalment. 
PART I. THE RELATIONSHIP OF THE ANGIOSPERMS 
TO THE GNETALES. 
Introduction. 
In our general paper ‘ On the Origin of Angiosperms \ the Gnetales 
were barely considered for reasons which we there stated as follows : — ‘ We 
may conclude that the study of the Gnetaceae does not, and does not seem 
likely to, help us in understanding the phylogeny of existing Angiosperms. 
It would appear more probable that a knowledge of the descent of the latter, 
1 Arber and Parkin (’07). 2 Sargant (’08) ; Bessey (’07). 
[Annals of Botany, Vol. XXII. No. LXXXVII. July, 1908.] 
