The Reconstruction of a Race of Primitive 
Angiosperms. 
BY 
ETHEL SARGANT, F.L.S. 
With twenty-one Figures in the Text. 
T HE origin of Angiosperms is perhaps the most important problem 
which botanical morphology has yet to solve. The advance of 
knowledge, which has thrown light on so many questions formerly to 
all appearance insoluble, seemed for a long time rather to obscure than 
to illuminate this subject. But of late some progress has been made. 
New facts have been contributed to the scanty evidence hitherto available, 
and several botanists have attempted to collect and piece together all such 
evidence, scattered, fragmentary, and insufficient as it is. 
On the one hand, our knowledge of the origin and development 
of the embryo-sac, both in Angiosperms and Gymnosperms, is more exten- 
sive and more precise. The structure of Angiospermous seedlings has been 
examined from a phylogenetic standpoint. 1 Dr. Wieland has described 
the bisexual strobili of the American Bennettiteae, which offer so many 
points of resemblance to the flowers of Angiosperms (89). 
On the other hand, we have treatises and speculations on the general 
question. The Morphology of Angiosperms (Coulter and Chamberlain, 19) 
is written throughout from a phylogenetic standpoint. The vexed ques- 
tion of the comparative antiquity of Monocotyledons and Dicotyledons has 
been revived on taxonomic (Hallier, 34) as well as on biological and 
anatomical grounds. 2 The origin of the Angiospermous flower has been 
discussed. 3 Finally, in a recent paper on the origin of Angiosperms (4), 
Messrs. Arber and Parkin have sketched out a possible line of descent for 
Angiosperms from Pteridosperms. 
The evidence thus brought together falls naturally under two heads. 
On one side we have an enormous mass of morphological detail concerning 
living Angiosperms— at once the largest, the best known, and the most 
1 Sargant (72) ; Tansley and Thomas (87) ; Anonymous (2) ; T. G. Hill (40, 41); A. W. Hill (39), 
2 Henslow (38) ; Balfour (8) ; Lyon (57, 58) ; Sargant (72, 73). 
3 Benson (9) ; Robertson, C. (68) ; Oliver, F. W. (62) ; Scott, D. H. (80). 
[Annals of Botany, Vol. XXII. No. LXXXVI. April, 1908.] 
K 
