330 1NSECTA. 



tion greatly depends upon our vigilance and knowledge of their habits. 

 Some of them are omnivorous such are the Termites, Ants, &c., 

 whose ravages are but too well known. Several of those which are 

 carnivorous, and all the species which feed on dead animal matters, &c., 

 are a benefit conferred on us by the Author of Nature, and somewhat 

 compensate for the inconvenience and injury we experience" from the 

 others. Some are employed in medicine, the arts, und our domestic 

 economy. 



They have numerous enemies : Fishes destroy many of the aquatic 

 species ; Birds, Bats, Lizards, &c., deliver us from a part of those which 

 inhabit the air or earth. Most of them endeavour to escape by flight or 

 running from the dangers that surround them, but some have recourse 

 to stratagem or arms. 



Having undergone their ultimate transformation, and being pos- 

 sessed of all their faculties, they continue their species : this aim once 

 accomplished, they soon cease to exist. Thus, each of the three finer 

 seasons of the year produces species peculiar to it. The females and 

 males of those which live in societies, however, enjoy a longer term of 

 life. Individuals hatched in autumn shelter themselves from the 

 rigours of winter, and reappear in spring. 



The species, like those of plants, are circumscribed within geographi- 

 cal limits. Those of the western continent for instance, a very few, and 

 all from the North, excepted, are strictly peculiar to it ; such also is the 

 case with several genera. The eastern continent, in turn, possesses 

 others which are unknown in the western. The Insects of the south of 

 Europe and north of Africa, and of the western and southern countries 

 of Asia, have a strong mutual resemblance. The same may be said of 

 those which inhabit the Moluccas, and more eastern islands, those of 

 the Southern Ocean included. Several northern species are found in 

 the mountains of southern countries. Those of Africa differ greatly 

 from the opposite portions of America. The Insects of Southern 

 Asia, from the Indies on the Sind eastward, to the confines of China, 

 are very much alike. The intertropical regions, covered with immense 

 and well watered forests, are the richest in Insects of any on the globe ; 

 Brazil and Guiana are particularly so. 



All general systems or methods relative to Insects are reduced essen- 

 tially to three. Swammerdam based his on their metamorphoses ; that 

 of Linnaeus was founded ou the presence or absence of wings, their 

 Jiumber, consistence, superposition, the nature of their surface, and on 

 the deficiency or presence of a sting. Fabricius had recourse to the 



