HISTORY OF PLANTS.» 4.05 
the botanical gardens which lie farther to’ the north. 
Perhaps these plants in time will dissenunate them- 
selves farther to the north, and they now actually 
spread, though slowly, in that direction. Who can 
say whether they may not, after many centuries, 
be disseminated a good deal farther, and whether 
other plants are not disseminated in the same way ; 
and thus, after some years, our Flora about Berlin 
will have gained many plants. 
Plants which are quickly propagated by seeds, 
and have luxuriant roots, must necessarily have been 
disseminated a great deal faster. And we should 
not wonder to see perhaps some of them dissemin- 
ated all over Europe, from one end to the other, 
especially such plants, the seeds of which are light, 
and can be easily carried off by the wind, which of 
course have been easier disseminated than those 
which have heavier seeds. Such plants have wan- 
dered from Lapland to the extreme corner of Italy, 
nay even as far as Africa. 
the spciege es Asia has a ae many eee 
i iC he ae ne Aa genanl and fu 
tween them the Helvetic Flora. It appears as if 
‘at an earlier period the continent was forming round 
the mountains of Europe, and reaching as far as 
the mountains of Asia, without much land, or at least 
very little, having then been formed round the moun- 
tains of the northwest coast of Asia. No wonder, 
therefore, that as far as the Ural and the Altaic range 
of mountains, the flat country next to us produces 
few Asiatic, but mostly European plants. ___ 
| Cc 3 North 
