250 
IIEM IP TER A. 
the head upwards, and sticking by their flattened inferior 
surface closely to the bark. On attempting to remove them 
they are generally crushed, and there issues from the body 
a dark-colored fluid. By pricking them with a pin, they 
can be made to quit their hold, as I have often seen in the 
common species, Coccus Hesperidum, infesting the myrtle. 
A little later the body is more swelled, and, on carefully 
raising it with a knife, numerous oblong eggs will be dis- 
covered beneath it, and the insect appears dried up and 
dead, and only its outer skin remains, which forms a convex 
cover to its future progeny. Under this protecting shield 
the young are hatched, and, on the approach of warm weath- 
er, make their escape at the lower end of the shield, which 
is either slightly elevated or notched at this part. They 
then move with considerable activity, and disperse them- 
selves over the young shoots or leaves. 
The shape of the young Coccus is much like that of its 
parent, but the body is of a paler color and more thin and 
flattened. Its six short legs and its slender beak ax - e visible 
under a magnifier. Some are covered with a mealy powder, 
as the Coccus Cacti, or cochenille of commerce, and the 
Coccus Adonidum, or mealy bug of our greenhouses. Others 
are hairy or woolly ; but most of them are naked and dark- 
colored. These young lice insert their beaks into the bark 
or leaves, and draw from the cellular substance the sap that 
nourishes them. 
Rdaumur observed the ground quite moist under peach- 
trees infested with bark-lice, which was caused by the drip- 
ping of the sap from the numerous punctures made by these 
insects. While they continue their exhausting suction of 
sap, they increase in size, and during this time are in what 
is called the larva state. When this is completed, the in- 
sects will be found to be of different magnitudes, some much 
larger than the others, and they then prepare for a change 
that is about to ensue in their mode of life, by emitting from 
the under side of their bodies numerous little white downy 
