DEVELOPMENT AND DISTRIBUTION OF LEGUMINOSZ. 383 
earth. Virgilia and Cladastris are examples among others 
of Sophorezee which have become acclimatised to harsh 
extratropical conditions. 
Sophora itself has demonstrated its adaptability to 
environment by penetrating extratropical North America, 
Asia, and South Africa. A modification of the genus, as 
Edwardsia, appears in Bourbon Isle, New Zealand, Easter 
Island, Hawaii and Chili. In its early stages Sophora could 
travel only under conditions of warmth, shelter and mois- 
ture. Under the changed climate of the later Tertiary, 
the genus adapted itself, in part, to colder and less hospit- 
able surroundings generally, and thus penetrated the 
temperate regions. Ina slightly different form known as 
Hdwardsia it reached New Zealand either by land connec- | 
tion or by marine currents.* Marive currents doubtless 
carried this Hdwardsia to Chili from New Zealand and from 
Chili to Hawaii. 
But both after the isolation of Australia from Asia and 
Africa and the great differentiation of climate in Post- 
Cretaceous time, as well as the draining of the Cretaceous 
epicontinental seas, great masses of sandy waste lands 
were produced, regions exhibiting great diurnal and annual 
variations in temperature. Prominent among these were 
the sandy regions of Australia and South Africa, as also 
the steppes and bleak open lands of Kurope and Asia. 
Regions such as these, where the conditions of climate are 
severe, appeared to act as a spur to floral activity in the 
production of xerophytic. types, provided that the rainfall 
did not fall below ten inches a year. The Sophorese made 
a grand response to these altered conditions, especially in 
Australia, where the development appears to have been 
rapid, but the handsome tree, or shrub, of the tropical 
# regions has been reduced there either to undershrubs or 
* Guppy (35). 
