Untitled - The Alfred Russel Wallace Website

362 NOTES OF A BOTANIST CHAP.
tation in all these and in hundreds of other cases
is invariably modified after the same fashion by the
colour of the waters. How it became what it is,
and how it came there at all, are questions not to
be discussed here.
After what has been said, it is scarcely necessary
to add that many species of plants which grow down
to the very coast in Guayana exist also in the
Peruvian province of Maynas that is, at the eastern
foot of the Andes, and even up to a height of a few
thousand feet in those mountains e.g. Humboldt's
Willow (Salix hnmboldtiana, W.) and the Cannonball
tree (Couroupita guianensis, Aubl.), called
Aia-uma or Dead Man's Head in Maynas ;
while
the proportion of Orinoco plants repeated on the
Amazon is much greater than that of the plants of
South Brazil. Nor does this uniformity of char-
acter, and the constant recurrence of certain species,
preclude the possibility of the flora being wonder-
fully rich ; for I have calculated that by moving
away a degree of either latitude or longitude I
found about half the species different ; while in the
numerous caatingas I have explored I always found
a few species in each that I never saw again, even
in other caatingas.
THE RELATIONS OF PLANTS AND ANIMALS
The importance of inquiries of this class is
obvious, even from a zoological point of view ; for
that an animal should flourish in any region it must
there find suitable food ;
and
there is perhaps no
part of the world where so large a proportion
of the
animals is so directly vegetarian in its diet. I have