REV, LEANDER S. KEYSER. 41 
many weeds persist in growing in my garden, but my specula- 
tions ought not to prevent my making a vigorous use of the 
hoe, which is the effective exterminator of the growths of weed- 
dom. The hearer may make his own application of the parable. 
Go out to the woods on a spring or autumn day, and watch 
the armies of Warblers, Vireos, Flycatchers, Woodpeckers 
and other birds busily plying their vocation of insect-hunting, 
and it willsoon dawn upon you that they must be the natural 
preservers of our forests. I verily believe that if, in some 
way, all birds could be kept out of our woodlands for two 
years in succession, when the third spring came, the trees, 
spite of the wooing of sun and rain and dew, would continue 
as gray and bare as when January snow-storms made dismal 
music through their leafless branches. The fecundity of the 
insect world is so great and their appetite for every green 
thing so ravenous that the earth would soon become a desert 
had not a natural check been provided. What can be 
more desolate than a tree stripped of its foliage by a troop 
of worms! .. In view of the usefulness of the birds I do not 
pity the slayer of them if he is stung and pestered half to 
death by gnats and mosquitoes when he prowls through the 
woods on his godless errand. 
It would be impossible to estimate arithmetically the 
service rendered by these winged scavengers of our wood- 
lands and fields. 
One spring day I witnessed the performance of a dainty 
Hooded Warbler (Sy/vania mitrata) for over an hour, It was 
in a sparse woodland by an old gravel-bank. During that 
time he was scarcely still a moment. No sooner had he 
caught and disposed of one insect than he swung out grace- 
fully on the air and captured another. If he averaged two 
insects a minute—and I think he did—he must have de- 
stroyed 120 in an hour; and if he worked only eight hours 
a day, he would have rid the woods of 960 insects more or 
less harmful to vegetation. Even if that should be twice too 
high an estimate per day, it must be remembered that the 
