432 Scientific Intelligence. 
“The most numerous, the most important, and often the most anomas 
lous facts in the existing distribution of plants, are explained by the ope- 
ration of causes anterior to those now in operation, or by the joint opera- 
tion of these and of still more ancient causes, sometimes of such as are 
primitive (connected with the earliest condition of the planet). The 
ary part. I have shown that in starting from an original fact, which it 
country, and ata certain time, we ought to be able, and sometimes are 
y 
able, to explain the following facts, chiefly by causes that operated pre- 
vious to our own epoch :—l, the very unequal areas occupied by Nat- 
_ “The only phenomena explicable by existing circumstances, are—I, the 
limitation of species, and consequently of genera and families, in every 
country wher p 
respectively to physicists and meteorologists, to geographers, to geologists, 
ists, and to 
view, viz: that the embryo is formed of (or in) the extremity of the pollen- 
tube,—has at length been definitely abandoned, both by its author, and — 
