HISTORY OF PLANTS. Se 
Plants which grow on hills, are, with regard to 
the shape of their leaves just the reverse, if compar- 
ed with aquatic plants, for their radical leaves are 
more or less entire and undivided, but the leaves on 
the stem become the more minutely intersected the 
higher up they are fixed to it. We find this, for 
instance, in the Scabiosa columbaria, Valeriana, and 
others. 
§ 351. 
Plants, as long as they remain in their natural un- 
cultivated state, retain mostly the same character, 
though sometimes they produce varieties. Those, 
however, do not occur so frequently as in plants 
which have been long cultivated by art. It is sin- 
gular indeed that animals when tamed, and plants 
when they have undergone the various management 
of art, easily change in form, colour, and taste, 
(§ 208). 
Alpine and polar plants grow larger in valleys or 
gardens ; their leaves gain in length and breadth, 
but their flowers are smaller, at least they do not 
grow larger like the rest of the plant. Plants of 
warm climates often change their appearance so 
much, that a pretty good practical botanist would 
scarcely be able to recognize them in their native 
countries. ‘The varicties of our species of fruit and 
oleraceous plants are innumerable. 
§252. 
Now, how does it come that our globe produces 
such an immense number of plants? Were all pro- 
duced 
