CLASS INSECTA. 23 



niorphosis. They have at first but six feet, or even none at 

 all, according to M. Savi ; the others, like the segments 

 on which they depend, are developed with age. 



There are few vegetable substances which are sheltered 

 from the voracity of insects ; and as those which are neces- 

 sary and useful to our wants are no more spared than the 

 others, they do us infinite mischief, particularly in such years 

 as are favourable to their multiplication. Their destruction 

 depends much upon our knowledge of their habits, and much 

 upon our vigilance. There are some of them omnivorous, 

 and of this number are the termites, ants, &c. whose ravages 

 are but too well known. Many of those which are carnassial, 

 and the species which live either on cadaverous, or excremen- 

 titious substances, may be considered as a benefit from the 

 hand of the Author of Nature, and as compensating in some 

 measure for the lossess and inconveniences we experience 

 from the others. Some insects are employed in medicine, in 

 the arts, and in domestic economy. 



They have also many enemies. The fish destroy a great 

 quantity of the aquatic species. Birds, bats, lizards, &c. 

 deliver us from a portion of those which inhabit the earth 

 and the air. The majority of insects endeavour to escape by 

 running or flying from the dangers which menace their exist- 

 ence ; but there are some which employ for the same pur- 

 pose peculiar stratagems, or the arms with which nature has 

 supplied them. 



When these animals are arrival at their final transforma- 

 tion, and in full possession and enjoyment of all their faculties, 

 they hasten to propagate their race, and when this object is 

 accomplished they soon cease to exist. Accordingly in our 

 climates, each of the three fine seasons of the year present us 

 with several species peculiar to itself. It appears, however, 

 that the females and the neuter individuals of those which 

 live in societies enjoy a longer career. Many individuals. 



