406 PRINCIPLES OF BOTANY, ETE. 
North America has a great number of the smaller 
European plants, and principally those of the Nor- 
thern Flora. Hence it appears probable, that both 
Europe and America were once joined, though they 
became afterwards separated. : 
§ 367. 
‘Yo obtain, according to our supposition, a just 
idea of the dissemination of plants over our globe, 
it would be highly necessary to visit: all high primi- 
tive mountains ; to mark down accurately the Flora 
of each mountain, but only as far as the foot, and 
ithe narrower valleys of the Alps, not to the very 
flat country. Was Europe examined after this plan, 
we would soon be able to determine from the num- 
ber of plants found, how the dissemination of them 
took place, what plants from this mountainous range, 
and what from another, found their way into the 
plains. | 
The coast of a country never exhibits to our view 
the plants of the interior. On. the former we find 
many plants which have come from. neighbouring 
countries. For this reason Asia, Africa, and Ame- 
rica, under the tropics, have upon their coasts 
many plants in common with each other. But if 
we proceed farther into the interior, the plants first 
seen disappear almost entirely, and the country 
now shews us its peculiar Flora, which is the greater 
if the ranges of mountains with many branches and 
of very varying soil are spread far over the country. 
At the Cape of Good Hope we find the Flora so 
rich, and at the same time, so unmixed and pure, 
Uh because 
