38 
ELEMENTS OE ENTOMOLOGY. 
reasons, that this buzzing sound is observable in a vast number of in- 
sects which have no poisers or balancers, such as wasps and bees. The 
two genera A.silux and Bombylita have no scale, and yet the noise per- 
ceptible in their flight is louder than in most of those which have both 
scale and poiscrs, as in the Musae. Nor does this noise issue from the 
poiser, either by striking on the scale or by any other means, since it 
is known that if the poisers, or both poiscrs and scales, be cut off, the 
same sound continues to be heard from the mutilated insects as before- 
There are many terms at present in use, to discriminate with greater 
precision the parts 1 have here described, and which should be under- 
stood by the student in entomology. I have thought it therefore best 
to insert them in alphabetical order at the end of the work, 
THE (ECONOMY OF INSECTS. 
Most animals retain during life the form which they receive at their 
birth. Insects are distinguished from these by the wonderful changes 
they undergo. The existence of an insect partakes of two, three," or 
four distinct states; and in eachol these differs most essentially in ap- 
pearance, organization, and manners of living. 
The changes through which the greater number of insects pass are 
from the Egg to the Larva, from the Larva to the Pupa, and from the 
Pupa to the Imago or perfect state. Exceptions occur to this : for 
some insects are viviparous; but the number of these is not consi- 
derable. 
Of the EGG state. The egg, containing the insect in its smallest size, 
is expelled from the ovary as in other oviparous animals. They are con- 
tained and arranged in the body of the insect, in vessels which vary in 
number and figure in different species. The same variety is found in 
the eggs: some are round, others oval, and some cylindrical. The 
shells of some arc hard and smooth, while others are soft and flexible- 
The eggs ol insects arc of various colours : some are found of al- 
most every shade of yellow, green, and brown, a few are red, and 
others black. Green and greenish are not unusual, and they are some- 
times speckled with darker colours, like those of birds. Some are 
smooth, and others beset in a pleasing manner with raised dots. 
Insects are instructed by nature to deposit their eggs in situation 5 
where their young ones will find the nourishment most convenient for 
them. Some deposit their eggs in the oak-leaf, producing there the 
red gall; others choose the leat of the poplar, which swells into a red 
bladder : and to a similar cause may be assigned the knob which is often 
seen on the leat ot the willow. The Lasiocampa ncustria glues its egg 5 
