276 USEFUL BIRDS. 
such insects. Without birds it is doubtful if crops of grass 
could be raised; for the grub of a single species of beetle, 
if unchecked, could readily destroy all the grass roots of 
our meadows ; and any one of several species of cutworms 
or army worms might be sufficient to destroy all the crops 
above ground. As it is, however, where the birds of the 
field are undisturbed they tend to hold the grass insects in 
check, so that the farmers are able to get good crops of 
grass without using any insecticides whatever. Therefore, 
we are largely indebted to birds for our grass crop. 
Wherever the numbers of birds are much reduced, there 
is danger of a corresponding reduction in the grass yield. 
Prof. J. Y. P. Jenks once told of an experience related to 
him regarding an occurrence many years ago in Bridgewater, 
Mass. A great hunt was held by the townspeople in the 
spring of the year, and so many birds were killed that their 
bodies were used to fertilize the soil. The following sum- 
mer the trees in that town were stripped of their leaves, and 
great patches of grass withered away and died. Such results 
must be expected wherever the number of birds in a region 
is suddenly and greatly reduced, and the pressure exerted by 
them upon the hosts of insects is as suddenly released. 
In preparing the garden or cultivated field, natural condi- 
tions are overturned. If in making a garden we desire to 
use a piece of land covered with trees, we must first clear it. 
By cutting trees and uprooting and burning stumps and 
underbrush we remove the natural shelter and nesting places 
for birds, and to a great extent destroy their food. Some 
woodland insects may persist, and later attack the growing 
crops; but the birds which formerly lived in the woods are 
driven away. 
If the land intended for our garden be natural meadow or 
prairie, we must dispose of the grass, and so the sod is turned 
under. As in the woodland, both the shelter and nesting 
places of the birds are destroyed, together with most of 
their food. Such insects as pass part of their lives in the 
ground, like the white grubs and cutworms, may survive and 
eventually come to live on the fruits of our labors; but the 
birds are driven out. 
