But such a swarm of locusts as we read of in Scripture, and frequently in the history of modern times and in our own country, would be comparatively tame and merely amusing affairs were they composed of our so-called "locust"--he of the whizzing timbrel in the sultry August noon. For this insect has no teeth, and could not bite a blade of grass if it wanted to. And herein we see one of the peculiarities which constitute him a "bug," and which also includes in the same company our woolly swarm upon the alder twigs. In place of teeth these insects are supplied with a beak for sucking the juices of plants. If we carefully examine the dense snowy mass we find it composed of small tufts closely crowded together, each tuft being borne upon the plump body of a small insect whose beak is deeply sunk into the tender bark. I have separated one of the little creatures, and furnished his portrait as he appears when viewed through a magnifying-glass, only the lower portion of his body being covered with the wool, his head and legs being usually concealed beneath the pluming growth of his neighbors. This feathery growth seems of the most delicate consistency--in truth, more suggestive of white "mould" than any other natural substance, and seems to proceed from pores in the plump body beneath it. The slightest breath wafts the cobwebby tips of the fringe, and the least rude touch easily dislodges it, exposing the round, naked body of what is now clearly seen to be an aphis, or plant-louse, which nature, for some reason, has seen fit to clothe with swan's-down. In early June the white down first appears on the alders in tiny patches here and there. This gradually extends down the stem, at length, perhaps, completely encircling it, and thus remaining for weeks, the full-grown aphis at last attaining a length of about three-sixteenths of an inch. A similar brood is sometimes seen in profusion on beech-trees and also on the apple-tree. But if we imagine that because these insects are without teeth they are therefore harmless, we are greatly mistaken. What they lack in individual effect they fully compensate for in numbers, and the combined attack of a girdle of thousands of these sucking beaks, for weeks absorbing the sap, may often result in the death of the branch beyond them. Dr. Harris, in his admirable work on "Insects Injurious to Vegetation," tells us that "in Gloucestershire, England, so many apple-trees were destroyed by these lice in the year 1810 that the making of cider had to be abandoned. So infested were many of the trees that they seemed, at a short distance, as if they had been white-washed."