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 birdsbusily plying their vocation of insect-hunting, 

 and it will soon 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 {Sylvania mitratd) 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 



