23G 
HEMIPTERA. 
the liinder extremity with two little tubes, knobs, or pores, 
from which exude almost constantly minute drops of a fluid 
as sweet as honey; their heads are small, their beaks are 
very long and tubular, their eyes are globular, but they have 
not eyelets, their antennae are long, and usually ta}>er to¬ 
wards the extremity, and their legs are also long and very 
slender, and there are only two joints to their feet. Their 
upper are nearly twice as large as the lower wings, are 
much longer than the body, are gradually Avidened towards 
the extremity, and nearly triangular; they are almost A^er- 
tical Avhen at rest, and cover the body aboA'e like a verj^ 
sharp-ridged roof. 
The winged plant-lice proAude for a succession of them 
race by stocking the plants AAnth eggs in the autumn, as 
before stated. These are hatched in due time in the spring, 
and the young lice immediately begin to pump up sap from 
the tender leaA^es and shoots, increase rapidly in size, and 
in a short time come to maturity. In this state, it is found 
that the brood, AAnthout a single exception, consists AA’holly 
of females, AA'hich are Avingless, but are in a condition imme¬ 
diately to continue their kind. Their young, liOAveA^er, are 
not hatched from eggs, but are produced aliA^e, and each 
female may be the mother of fifteen or tAventy young lice 
in the course of a single day. The plant-lice of this second 
generation are also AAnngless females, AA’hich groAV up and 
haA’e their young in due time; and thus brood after brood* 
is produced, eA’en to the seA^enth generation or more, Avith- 
out the appearance or interA’ention, throughout the AA’hole 
season, of a single male. This extraordinary kind of prop¬ 
agation ends in the autumn AA’ith the birth of a brood of 
males and females, Avhich in due time acquire AA’ings and 
pair; eggs are then laid by these females, and Avith the 
death of these Avinged indiAuduals, Avhich soon folloAvs, the 
race becomes extinct for the season. 
Plant-lice seem to loA^e society, and often herd too-ether 
in dense masses, each one remaining fixed to the plant by 
