COMMON CHER KY-T REE. 2G3 
passing through the trees, became charged with a very disagreeable and sicken- 
ing odour, given out by these slimy creatures. ***** The slug-worms 
come to their growth in twenty-six days, during which period they cast their 
skins five times. Frequently, as soon as the skin is shed, they are seen feeding 
upon it; but they never touch the last coat, which remains stretched out upon 
the leaf. After this is cast off, they no longer retain their slimy appearance, and 
olive colour, but have a clear yellow skin, entirely free from viscidity. They 
change also in form, and become proportionably longer ; and their head and the 
marks between the rings are plainly to be seen. In a few hours after this change, 
they Leave the trees, and, having crept, or fallen to the ground, they burrow to 
the depth of from one inch to three or four inches, according to the nature of the 
soil. By moving their body, the earth around them becomes equally pressed on 
all sides, and an oblong-oval cavity is thus formed, and is afterwards lined with 
a sticky and glossy substance, to which the grains of earth closely adhere. 
Within these little earthen cells or cocoons, the change of the chrysalides takes 
place; and, in sixteen days after the descent of the slug- worms, they finish their 
transformations, break open their cells, and crawl to the surface of the ground, 
where they appear in the fly form. These flies usually come forth between the 
middle of July and the first of August, and lay their eggs for a second brood of 
slug- worms. The latter come to their growth, and go into the ground, in Sep- 
tember and October, and remain there till the following spring, when they are 
changed to flies, and leave their winter quarters. It seems that all of them, 
however, do not finish their transformations at this time ; some are found to 
remain unchanged in the ground till the following year ; so that, if all the slugs 
of the last hatch in any one year should happen to be destroyed, enough, from a 
former brood, would still remain in the earth, to continue the species." Among 
the natural enemies to these insects, are mice, and other earth-burrowing animals, 
which destroy many of them in their cocoons, and it is probable that other insects 
and birds prey upon them, both in the larvae and in the winged states. Pro- 
fessor Peck has described a minute ichneumon-fly, (Encyrtus,) which punctures 
the eggs of the slug-fly, and deposits in each, a single egg of its own. These 
minute eggs, in due time, produce little maggots, which live in the shells of the 
eggs of the slug-flies, devour their contents, and afterwards are changed to chrys- 
alides, and then to flies, like the parent. Thus, by these atoms of existence, 
myriads of the eggs of slug-flies are rendered abortive, an admirable illustration 
of the order of Providence, which prevents the earth from being overrun with 
one species, by appointing another race to keep them down. Ashes or quick- 
lime, sifted or thrown on the trees infested by these slugs, has proved effectual 
in checking their depredations, and Mr. Haggerston's almost universal remedy, 
(a solution of whale-oil soap and water,) has been found to be equally effectual. 
The common cherry, as well as the peach-tree, sometimes suffers severely from 
the attacks of the borers, produced by a large copper-coloured beetle (Buprestis 
divaricata, Say.) 
Properties mid Uses. The wood of the common cherry-tree is of a reddish 
hue, more or less veined with darker shades, and somewhat resembles, in its 
general appearance, some of the ordinary kinds of mahogany. When wel" sea- 
soned, its weight does not usually exceed forty-five pounds to a cubic foot. It is 
sufficiently tender to be easily wrought, and from the openness of its grain, it is 
readily coloured. In those parts of Europe where mahogany is costly, it is some- 
times employed in the manufacture of chairs, the frames of mirrors, and other 
minor works. The fruit of the cherry, although a favourite food with most per- 
sons, has ever been found more tempting than wholesome. Pliny says, " this 
fruit will loosen and hurt the stomach ; but when hung up and dried, has a con- 
trary effect." He relates that some authors have affirmed that cherries ^aten 
