THE SPARROW; ITS VIRTUES. 29% 
its homes year after year? And have not cockney 
“sportsmen”: and village gunners treated it as the 
legitimate victim of their love of purposeless 
slaughter ? 
And yet we argue that the bird has been allowed 
to increase, almost without restraint, owing to our 
destruction of hawks! If, instead of persecuting 
those birds, we could have multiplied them twenty- 
fold, if we could have allowed them to carry out their 
mission undisturbed and unmolested in any way, they 
would not—they could not—have killed one-tenth of 
the sparrows which we ourselves have slain. 
Once more—as I have already shown—by our folly 
in killing off the various insectivorous creatures we 
have allowed the insects to gain the upper hand. 
More than that, the great increase in the area of 
cultivated ground has brought about, in accordance 
with Nature’s unvarying law, a corresponding increase 
in the number of insects which find their food in the 
crops which we raise thereon. 
Briefly stated, Nature’s system is this. If there 
be one square mile of ground planted with any one 
vegetable, a certain number of insects feeding upon 
that vegetable will be found upon that piece of land; 
and the number will vary little, upon on average, 
from one year to another. But, if we double, treble, 
or quadruple the space thus planted, we shall also 
double, treble, or quadruple the number of the 
insects at the same time; for an abundant food- 
supply is always the principal factor in bringing about 
the increase of an animal. 
N 2 
