136 PLANTS AND ANIMALS. [CHAP. 
up the contest. If they can find mischief going on in a 
garden or field where the birds have not been meddled 
with, they begin to triumph, unless they are aware of the 
true answer. ‘That answer is given by some lover of rural 
life—some observer of birds and insects—who says that a 
single brood of nestlings in the ivy or the hedge has been 
seen to devour hundreds of grubs or other insects per day, 
showing that if Nature were let alone, there would be millions 
so got rid of in g mile (as, indeed, we knew before by the 
French report); and if, after the insects had been left to 
their natural enemies, there were still too many, what might — 
not the infliction become if they were left without check ? 
The check ought this year to have been very strong. The 
swallows came early, the sparrows burst out of the hedges 
in crowds, the blackbirds and finches have been whistling, 
and piping, and chirping, as if the world were all their own. 
But this is only where they are allowed to live; and there 
are too many parishes and districts where they are not. 
This is no trifle, and the present’ season ought to be a 
lesson for future years.” 
It is a melancholy picture, but a true one, of the 
effects wrought by ignorance, and well illustrates the 
fact that birds are the natural protectors of plants. 
Insects are the checks upon plants to prevent their 
too rapid increase; but if the insects should become 
too numerous, certain species of plants would dis- 
appear altogether. To prevent this the small birds 
are set as a check upon the insects, and that these 
birds should not increase unduly, the smaller birds of 
prey keep them in check. Thus every created thing 
is connected indirectly with every other, and the most 
perfect harmony of Nature is the result. Man has 
the power of modifying these arrangements, and uses 
