544 
HYMENOPTERA. 
the irritating punctures of these insects, that the attention 
of cultivators is at all likely to be drawn to them. There 
are some two-winged flies, and also some other insects, 
which produce various kinds of excrescences or galls on 
plants; but these now under consideration are very small, 
four-winged insects, belonging to the order Hymeno'ptera^ 
and distinguished by the following peculiarities. The head 
is small; the antennae are rather short, slender, and thread¬ 
like ; and the thorax is thick and hunched. The abdomen 
or hind body, viewed sidewise, appears round or oval, hut 
it is sharp-edged above and below, very thin or pinched 
up at the sides, and is hung to the thorax by a very short 
and slender stem. The fore wings are rather long, and 
have only a few veins in them ; the hind wings are small, 
and seemingly veinless. The borer of the females is very 
long, and slender, concealed in the under side of the hind 
body, the curvature whereof it follows, and is capable of 
beino; straio:htened and thrust out of a narrow chink, which 
is covered by two little, grooved, sheath-like pieces, that 
serve to conduct the e^ffs into the holes made with the 
instrument. 
The genus containing most of the gall-flies was called, 
by Geoffroy, Diplolepis^ that is, double scales, on account 
of tlip two pieces that cover the opening for the borer in 
the hinder part of the abdomen. The same insects, how¬ 
ever, had previously been, placed by Linnaeus in the genus 
Cynips^ so called from a word used by ancient authors to 
designate some small piercing insect. The Linnaean name, 
though for some time rejected, has been restored to the gall¬ 
flies, which accordingly are now included in a family called 
Cynipidje. The punctures, made by these insects in the 
leaves, buds, stems, and roots of plants, are followed by 
swellings of the wounded parts, which increase rapidly in 
size, and become spongy or pulpy within. The thin-skinned 
eggs, dropped into the punctures, grow awhile, by absorb¬ 
ing the sap around them, and, when at length they are 
