THE INSECTA. 271 
distinct ; that they are reproduced from eggs; and, in conclusion, that the 
different parts we have mentioned are not complete until the creature has 
passed through several successive changes, called metamorphoses, —a gen- 
eral idea may be formed of what is meant in zodlogy by the word ‘in- 
sect.’” 
There are but few vegetable substances which do not fall under the attacks 
of insects; and as those which are useful or necessary to man are not less 
liable to them than the others, they often cause great damage, especially in 
seasons favorable for their multiplication. ‘Their destruction depends greatly 
on our knowledge of their habits, and on our own vigilance. Some are 
omnivorous, such as the White Ants, Ants, &Ge., of which the ravages are 
too well known. Many among these are carnivorous ; and the species which 
feed upon carcasses or excrement are a benefit conferred on us by the Author 
of Nature, and compensate, in some respect, for the losses and inconven- 
iences which the others cause to us. Some species are employed in medi- 
cine and in the arts, as well as our domestic economy. They have also 
many enemies: fishes destroy a great quantity of aquatic species; many 
birds, bats, lizards, &c., rid us of many of those which live upon the 
ground or in the air. The majority strive to avoid the dangers which 
menace their existence, by flying or running away; but there are some 
which employ for this purpose particular stratagems or natural arms, and 
exhibit reasoning powers of a most extraordinary character, as will appear 
as we place under examination the several genera. 
“ Like vegetables, the species of insects are subject to geographical limits. 
Those, for example, of the New World (with the exception of a small num- 
ber of the northern species) are essentially peculiar to it: it also possesses 
many genera equally peculiar. The Old World, on the other hand, pos- 
sesses others unknown in America. The insects of the south of Europe, 
North Africa, and the west and south of Asia, have great general resem- 
blance. It is the same with those of the Moluccas, and the more eastern 
islands, including those of the South Sea. Many species of the north are 
found in the mountainous regions of more southern climates. Those of 
Africa differ greatly from those of the opposite countries of America. The 
insects of Southern Asia, commencing from the Indus, or Sind, and going 
to the east as far as the confines of China, have features greatly resembling 
each other. The intertropical regions, covered with immense damp for- 
ests, are the richest in insects; and in this respect Brazil and Guiana are 
the most highly favored. 
* Arrived at their last transformation, and enjoying all their faculties, they 
hasten to propagate their race; and when this is performed, their existence 
soon terminates. Thus, in our climate, each season of the year (winter 
