. 
important problems in natural history. Botanists ate now in- 
asta some facts that may help to unravel the causes which 
eal exposed to accidental and unaccountable migrations. The 
ssa Im tree found in the quaternary strata of Northern Rus- 
4 than from shells and animal remains only, This expecta- 
bis 18 confirmed by the flora of the different strata of the coal- 
the — of plants, for each bed o 
on, the most interesting, by far, 1s the one 
aude by Dr, John Evans in his U. S. Survey ing expedition of 
gon territory, Vancouver Island, &. A description of these 
fenoe atts appears just now to be a valuable contribution to 
fees & full description of the fossil leaves with cor 
It will be ‘ ; ; 
S0me era teresting to mention and compare at the same time 
Pecies of fosail’ plants found by Prof. Jas. M. Safford in 
