Aveust 11, 1899. ] 
unlike plants and insects, depend on man 
almost entirely for their distribution from 
one continent to another, and, with few 
exceptions, are intentionally introduced. 
Cases of accidental distribution are con- 
fined almost entirely to rats and mice, 
which readily find their way to nearly all 
parts of the world by means of vessels. 
Fhe question of preventing the introduc- 
tion of noxious mammals and birds is ap- 
parently simple, and doubtless would be 
comparatively easy to deal with were it not 
for the general ignorance or indifference re- 
garding the dangers of ill-advised acclima- 
tization. 
The mammals and birds which have 
thus far proved most troublesome when in- 
troduced into foreign lands are nearly all 
natives of the Old World. Beside cats, 
rats and mice, they include the rabbit, 
stoat, weasel, house sparrow and starling 
of Europe, and the mongoose and mina of 
India. The so-called flying foxes, or fruit- 
eating bats, are very destructive in New 
South Wales and Queensland, and are con- 
sequently a source of danger, for, although 
not yet actually introduced, they are likely 
to be carried to Hawaii and other islands 
in the Pacific. Some birds usually con- 
sidered beneficial in their native homes are 
likely to prove injurious elsewhere, such as 
the European skylark, green linnet, black 
thrush, or blackbird, and the great titmouse, 
or ‘ Kohlmeise. 
It will hardly be necessary to take up 
each of these species in detail. The his- 
tory of the rabbit in Australia and New 
Zealand, its prodigious increase despite 
lavish expenditures for its destruction, and 
the enormous export trade in skins and 
eanned rabbits which has recently sprung 
up, are too well known to require repetition 
here. The stoats and weasels liberated in 
New Zealand to kill off the rabbits have 
also become a pest and threaten to exter- 
minate certain native birds. The mon- 
“SCIENCE. 
175 
goose, carried to Jamaica, in 1872, to aid 
in controlling the rat plague, increased 
almost as fast as the rabbits in the Antipo- 
des, and, although it effectually reduced the 
number of rats, the advantage proved to be 
temporary and dearly bought. The animals 
increased until they spread over the whole 
island and became a greater pest than the 
rats on account of their wholesale destruc- 
tion of poultry, game, ground-nesting birds 
of various kinds, reptiles and even fruits. 
The decrease of birds was followed by a 
marked increase in certain insect pests, but 
recent reports indicate that the mongoose is 
diminishing somewhat in numbers and 
some of the birds are increasing, so that 
both native and introduced species are 
adapting themselves to new conditions. In 
Hawaii the record is much the same, al- 
though the mongoose has not yet become 
quite such a nuisance as it has in Jamaica. 
The English sparrow was brought to Amer- 
ica less than fifty years ago, but is now 
present in every State and Territory, with 
half a dozen exceptions, and is known as a 
pest to nearly every one in the eastern 
United States. It has begun to spread in Ar- 
gentina, while in Australia it is even more 
troublesome than in this country. It has 
also gained a foothold in Hawaii and on 
numerous islands in the Atlantic, Pacific 
and Indian Oceans. 
When it is considered that in nearly 
every case the species just mentioned were 
deliberately and intentionally introduced, 
under the mistaken idea that they were 
beneficial, it is evident that immense loss 
may result from the well-meaning efforts of 
thoughtless or ignorant persons, for an in- 
jurious species is likely to spread more 
surely and steadily than a contagious dis- 
ease. The danger from such experiments 
is too real to be dealt with lightly and is 
now beginning to be realized. Cape Colony 
prohibits the importation or keeping of 
rabbits except under strict regulations. 
