THE BOTANICAL CONGRESS AT FLORENCE. 213 
of a silicified trunk found in the desert near the pyramids of 
principal. glaciers, and the Swiss Alps received their flora first from 
_ the south, and then from the east and west. The author then asks, 
times t was more moisture in the climate of Europe, and con- 
sequently the flora was richer and more varied. After a time the 
climate became dryer, and as the glaciers retired man nts were 
n, for : ; 
one locality, it is natural to suppose that formerly it had occupied 
ithe intermediate ground, and that the glacier coming through the 
| = of it had divided it into two groups. He was also unable to 
Valley, which must have very recently been freed from glaciers, is 
"amarkably rich in rare plants.—M. T¢hiatcheff remarked that in 
Asia Minor he could find no trace of glacial action which could help to 
i Timiriazeff read a paper on 
