American Association at Dubuque. 297 
a tertiary species, and one nearly allied to Sequova Langsdor, z, 
which in turn is a probable ancestor of the common Californian 
redwood; has furnished to Lesquereux in North America, the 
remains of another ancient Sequoia, a Glyptostrobus; a Liquid- 
ambar which well represents our sweet-gum tree; oaks analogous 
iving ones; leaves of a plane tree, which are also in the 
tertiary, and are scarcely distinguishable from our own Platanus 
talis ; o 
undistinguishable from our living species.” I eed not con- 
Our actual flora are marked in the cre us period, and have 
come to us after passing, without notable changes, through the 
te formations of our continent. 
rilary 
According to these views, as regards plants at least, the 
adaptation to successive times and changed conditions has been 
tions, TI, for one, cannot doubt that the present existing species 
are the lineal successors of those that garnished the earth in 
around us are to their conditions now. Order and exquisite 
Am. Jour. So.—Turrp Serres, Vor. IV, No. 19.—Oor., 1872. 
oD 
