ned to Europe. In their transplantation to Australia they were
carried to a country with a different climate and among new
surroundings. Yet the rabbits flourished, and within comparatively few
years increased to such an extent as to become a burden and pest to the
country. It may be remembered though, that, owing to the complete
absence of small carnivores, which act with us as a check upon the too
rapid increase of this rodent, the speed with which it established
itself in the new surroundings is not so very surprising.

Many of the English settlers in the New World felt that America lacked
the presence of our familiar birds. The homely sparrow was therefore
brought over, with the result that the Agricultural Department of the
United States is now devising means for its destruction, so rapid has
been its increase.

Similarly, the inhabitants of Jamaica, annoyed by the great profusion of
rats in their island, sent over to India for a number of mongoose. These
have decimated the rats since their arrival, but they have multiplied to
such an extent as to be a serious menace to the native fauna.

To give an instance nearer home, the Capercaillie (_Tetrao urogallus_)
was successfully introduced into Scotland in 1837. From its different
centres of distribution it is spreading in all directions where
sufficient cover is obtainable. But this case differs from the others
very materially, in so far as this bird was formerly a native of
Scotland, and only became extinct during the last century.

However, although there are many examples of undoubtedly successful
introductions by human agency, quite as many, or perhaps more,
unsuccessful ones might be quoted. In fact, it is by no means easy to
establish a species in any new locality. Frequently it happens that the
species seems to be on the increase at first, but then there is a
decline, and after a few years the new plantation has entirely vanished.
In other cases, the species disappears immediately after the
introduction takes place, or lingers on for many years if it receives
special and uninterrupted protection.

It may not be generally known that the English Hare (_Lepus Europaeus_)
is not found in Ireland, where the Mountain Hare (_Lepus variabilis_)
alone occurs. Attempts to acclimatise the English species have been made
in a number of places in Ireland, but many of them have been failures,
and not one of them has been a signal success.[4] Similarly, the
endeavour to i