6 
INTRODUCTION. 
the use of its legs ; as it grows larger it is soon obliged to 
cast off its skin, and, after one or two moultings, its body 
not only increases in size, but becomes proportionally longer 
than before, while little stumplike wings begin to make their 
appearance on the top of the back. After this, the grassy 
hopper continues to eat voraciously, grows larger and larger, 
and hops about without any aid from its short and motion- 
less wings, repeatedly casts off its outgrown skin, appearing 
each time with still longer wings, and more perfectly formed 
limbs, till at length it ceases to grow, and, shedding its skin 
for the last time, it comes forth a perfectly formed and ma- 
ture grasshopper, with the power of spreading its ample 
wings, and of using them in flight. 
Hence there are three periods in the life of an insect, more 
or less distinctly marked by corresponding changes in the 
form, powers, and habits. In the first, or period of infancy, 
an insect is technically called a larva , a word signifying a 
mask, because therein its future form is more or less masked 
or concealed. This name is not only applied to grubs, cat- 
erpillars, and maggots, and to other insects that undergo a 
complete transformation,’ but also to young and wingless 
grasshoppers, and bugs, and indeed to all young insects be- 
fore the wings begin to appear. In this first period, which 
is generally much the longest, insects are always wingless, 
pass most of their time in eating, grow rapidly, and usually 
cast off their skins repeatedly. 
The second period — wherein those insects that undergo a 
partial transformation retain their activity and their appe- 
tites for food, continue to grow, and acquire the rudiments 
of wings, while others, at this age, entirely lose their larva 
form, take no food, and remain at rest in a deathlike sleep — 
is called the pupa state, from a slight resemblance that some 
of the latter present to an infant trussed in bandages, as was 
the fashion among the Romans. The pupae from caterpillars, 
however, are more commonly called chrysalids, because some 
of them, as the name implies, are gilt or adorned with golden 
