WILD ANIMALS IN CAPTIVITY 
exist : as an illustration we may point to such plants as 
the thistle, the seed of which is provided with a most 
beautiful and perfect floating apparatus, which causes it 
to be wafted by the slightest current of air for miles 
across the country, aye, even to be borne by the wind 
beyond the sea, which, rapidly becoming disseminated 
over the earth, are the means of attracting and of inducing 
to migrate the creatures that live upon their seed. 
A singular confirmation of this may be found in the 
partially changed habits of the common goldfinch. Since 
the formation in this country of railways the thistles have 
increased on the uncultivated banks or sides of the 
various cuttings on the different lines, and goldfinches, as 
they feed greatly upon thistle seed, have congregated in 
the localities where that weed abounds, and have become 
comparatively rare in places where formerly they were 
numerous. 
The introduction and cultivation of a particular kind 
of grain or fruit into a country will tend to attract some 
of the wild animals from the surrounding forest to the 
cultivated ground, and to increase their numbers by the 
food so readily obtained. An instance of this kind is 
causing the cultivators of the grape in Australia much 
trouble, as since the introduction of the vine to that 
country, the large fruit-eating bats {Pteropus ’polioccplialui) 
have committed much damage. Collecting in large 
numbers after dark, they devour the grapes in prodigious 
quantities, and as their numbers appear on the increase, 
it is doubtful whether the cultivation of the grape can be 
continued with any prospect of success in Australia. It 
is said that the authorities in Australia were at one time 
in great fear of the escape of lions, tigers, or other large 
carnivora from travelling collections, for should these 
formidable creatures only obtain a footing, the abundance 
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