DEVELOPMENT AND DISTRIBUTION OF THE LEGUMINOSZ. 359 
evidence is that the angiosperms developed on the old 
lands of the eastern part of North America, and that until 
the close of the Lower Cretaceous they had only spread 
westward as far as Kansas and the Black Hills, northward 
as far as Greenland, and eastward to the coast of Portugal, 
but not to Hurope generally, nor to the western part of 
North America, for they do not appear in the Kootenay or 
the Shastan series. . . . Inthe most typical region on 
the Atlantic coast, nearly half the known 800 species of 
Comanchean age are angiosperms. They beganin marked 
minority in the lowest Potomac (Lower Oretaceous) and 
increased to an overwhelming majority in the uppermost 
beds. The earliest forms are ancestral, but not really 
primitive, and throw little light on the derivation of 
the angiosperms. While some are undifferentiated, the 
majority bear resemblances to modern genera. . . . ” 
(p. 133). 
Scott’ refers to the great work of Wieland in describing 
the Bennettites found in the Upper Jurassic and Lower 
Cretaceous rocks of Western America. This group of 
plants appears to be intimately related to the modern 
Cycadacez and the Angiosperms are supposed to have 
descended through these Bennettites. The Dicotyledons 
are believed to be older than the Monocotyledons, the 
latter descending in turn through the Polycarpice’ of 
the Dicotyledons. 
Adverting to the question of the geographical distribu- 
tion of the Dicotyledons as time progressed, it may be noted 
that by the close of the Upper Cretaceous they had spread 
over a great portion of the world and, moreover, by the 
close of that period, they had become highly differentiated. 
It would appear, indeed, as though a new yet cosmo- 
politan set of geographic and organic conditions had 
1 The Evolution of Plants. Home University Library, p. 80. 
2 Strasburger. Text Book of Botany. 1912, p. 525. 
