The Significance of the ‘Foliar Ray’ in the 
Evolution of Herbaceous Angiosperms. 
BY 
E. W. SINNOTT, 
Connecticut Agricultural College , 
AND 
I. W. BAILEY, 
Bussey Institution , Harvard University . 
With Plates XVIII and XIX and one Figure in the Text. 
I N 1914 the writers 1 presented in this Journal a body of evidence in 
support of the suggestion of Hallier, 2 of Eames, 3 and of others that 
herbaceous angiosperms are derived from arborescent or fruticose ancestors. 
In that paper we not only discussed evidence from the fields of palaeobotany, 
phylogeny, and anatomy, but paid particular attention to the geographical 
distribution of the various growth forms of Dicotyledons and its bearing on 
the problem of the evolution of herbs. In the eight years that have elapsed 
since the appearance of our paper, the anatomical aspect of this problem has 
been taken up in a number of contributions from Professor Jeffrey’s labora- 
tory. This series has culminated in two recent papers by Jeffrey and 
Torrey 4 in which a vigorous attempt is made to discredit our work. The 
unfortunate tone of this attack we can afford to ignore, but, in view of the 
misrepresentation of our position which these and earlier papers contain, 
and because of the confusion which they have introduced into the discussion, 
we feel that it is wise to restate our conclusions in the light of all the facts 
which have been brought forward, and to endeavour to clarify the real points 
at issue. 
1 Sinnott, E. W., and Bailey, I. W. : Investigations on the Phylogeny of the Angiosperms: 
No 4. The Origin and Dispersal of Herbaceous Angiosperms. Ann. Bot., xxviii. 547-600. 
2 Hallier, H. : Ein zweiter Entwurf des natiirlichen (phylogenetischen) Systems der Bliiten- 
pflanzen. Ber. Dent. Bot. Gesellsch., xxiii. 85-91, 1905. 
3 Eames, A. J. : On the Origin of the Herbaceous Type in the Angiosperms. Ann. Bot., 
xxv. 215-24, 1911. 
4 Jeffrey, E. C., and Torrey, R. E. : Physiological and Morphological Correlations in Her- 
baceous Angiosperms. Bot. Gaz., lxxi. 1-31, 1921. Ibid. , Transitional Herbaceous Dicotyledons. 
Ann. Bot., xxxv. 227-49, 1921. 
[Annals of Botany, Vol. XXXVI. No. CXLIV. October, 1922.] 
O O 2 
