168 INSECTS INJURIOUS TO VEGETATION. 



the exact period of seventeen years was observed, they should 

 have returned in 1803. Circumstances may occasionally retard 

 or accelerate their progress to maturity, but the usual interval is 

 certainly seventeen years, according to the observations and testi- 

 mony of many persons of undoubted veracity. Their occur- 

 rence in large swarms at lf)ng intervals, like that of the migratory 

 locusts of the east, probably suggested the name of locusts, which 

 has commonly been applied to them in this country. The fol- 

 lowing extract from a letter* from the late Rev. Ezra Shaw 

 Goodwin, of Sandwich, contains some interesting particulars which 

 this gentleman had the kindness to communicate to me. 



" I have not been unmindful of what you said to me respecting 

 the locust insects, nor of the promise I made you with respect to 

 them. They appeared in this town in the year 1821, in the 

 middle of June. Their last previous appearance was in 1804, 

 and their last, previous to that, was in 1787. I ascertained these 

 periods from the statements of individuals, who remembered that 

 it was locust-year, when this or that event occurred ; as, when 

 this one was married, or that one's eldest son was born ; events, 

 the date of which the husband or the parent would not be very 

 likely to forget. The remembrance of all, though fixed by dif- 

 ferent events, concurred in establishing the same years for the ap- 

 pearance of the locusts. 



" I first took notice of them in 1821, on the 17th of June, 

 from their noise. They appeared chiefly in the forests, or in 

 thickets of forest-trees, principally oak. Their nearest distance 

 from my dweUing cannot be far from a mile ; yet, at a still hour, 

 their music was distinctly heard there. On going to visit them, 

 I found the oak-trees and bushes swarming with them in a winged 

 state. They came up out of the ground a creeping insect. Very 

 soon, after they had arrived on the surface of the earth, the skin, 

 or rather the shell of the insect burst upon the back, and the 

 winged insect came forth, leaving the skin or shell upon the earth, 

 in a perfect form, and uninjured, saving at the rupture on the 

 back ; showing an entire withdrawing of the living animal, as much 

 so as does the snake's skin after he has left it. Thus these skins 



* Dated Oct. 19, 1832. 



