6 INTRODUCTION. 



the use of its legs ; as it grows larger it is soon oLliged to 

 east otf its skin, and, after one or two raoul tings, its body 

 not only inereases in size, but beeomes proportionally longer 

 than before, while little stump-like wings begin to make their 

 appearance on the top of the back. After this, tlie grass- 

 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 wangless 

 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 oflp their skins repeatedly. 



The second period — wherein those insects that undergo a 

 ])artial transformation retain their activity and their appe- 

 tites for food, continue to grow, and acquire the rudiments 

 of Avings, while others, at this age, entirely lose their larAa 

 form, take no food, and remain at rest in a deathlike sleep — 

 is called the j9?/j»>a 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 puptv fi'om caterpillars, 

 hoAvever, are more commonly called chrysalids, because some 

 of them, as the name implies, are gilt or adorned with golden 



