Ley OUR BIRD ALLIES. 
poses by our own act, and in no sense a provision of 
nature. The case, indeed, is one of the many in 
which man has taken upon himself to alter, and, as 
he supposed, to improve upon natural arrangements, 
only to find that his short-sighted policy leads to 
results which he never anticipated, and leaves him in 
a position far worse than that from which he sought 
by a bold step to extricate himself. Has he not met 
with precisely similar retribution in other cases? Did 
he not, urged by sentimentally patriotic motives, plant 
the thistle upon Australian soil, to find, in the course 
of a few years, that it had become a pest never to be 
eradicated? Did he not likewise introduce the sweet- 
briar, for the sake of old associations, and afterwards 
strive in vain, even with the aid of ropes and cart- 
horses, to prevent it from spreading in like manner ? 
Did he not import rabbits into the same country, 
and afterwards incur the expenditure of millions of 
money in the vain attempt to reduce their increase ? 
Acclimatisation—more especially in such a country 
as Australia or New Zealand, the natural denizens of 
which, both animal and vegetable, are comparatively 
weak and feeble—is always a highly dangerous ex- 
periment ; and when, knowing this by reason of many 
a disastrous failure in the past, we wilfully undertake 
it, we have only ourselves to blame if the results are 
not quite what we could wish. 
What wonder if the sparrow, both in America and 
New Zealand, should turn from a diet of insects to 
one of grain and fruit? Does not even man himself 
alter his food in accordance with the climate? Does 
