nce as
the native plants of a district. Man is, in truth, continually striving
to diminish the natural diversity of the _stations_ of animals and
plants in every country, and to reduce them all to a small number fitted
for species of economical use. He may succeed perfectly in attaining his
object, even though the vegetation be comparatively meagre, and the
total amount of animal life be greatly lessened.

Spix and Martius have given a lively description of the incredible
number of insects which lay waste the crops in Brazil, besides swarms of
monkeys, flocks of parrots, and other birds, as well as the paca,
agouti, and wild swine. They describe the torment which the planter and
the naturalist suffer from the musquitoes, and the devastation of the
ants and blattae; they speak of the dangers to which they were exposed
from the jaguar, the poisonous serpents, crocodiles, scorpions,
centipedes, and spiders. But with the increasing population and
cultivation of the country, say these naturalists, these evils will
gradually diminish; when the inhabitants have cut down the woods,
drained the marshes, made roads in all directions, and founded villages
and towns, man will, by degrees, triumph over the rank vegetation and
the noxious animals, and all the elements will second and amply
recompense his activity.[967]

The number of human beings now peopling the earth is supposed to amount
to eight hundred millions, so that we may easily understand how great a
number of beasts of prey, birds, and animals of every class, this
prodigious population must have displaced, independently of the still
more important consequences which have followed from the derangement
brought about by man in the relative numerical strength of particular
species.

_Indigenous quadrupeds and birds extirpated in Great Britain._--Let us
make some inquiries into the extent of the influence which the progress
of society has exerted during the last seven or eight centuries, in
altering the distribution of indigenous British animals. Dr. Fleming has
prosecuted this inquiry with his usual zeal and ability; and in a memoir
on the subject has enumerated the best-authenticated examples of the
decrease or extirpation of certain species during a period when our
population has made the most rapid advances. I shall offer a brief
outline of his results.[968]

The stag, as well as the fallow deer and the roe, were formerly so
abundant in our island, that, according to