2 INSECTS. 



or breathing-holes, distributed in a series or row 

 on each side the whole length of the abdomen; 

 and these spiracles or breathing-holes are supposed 

 to communicate with a continued chain, as it were, 

 of lungs, or. at least of parts analogous to them, 

 distributed throughout the whole length of the 

 body. The head is furnished with a pair of what 

 are termed Antennae, or horns, which are extremely 

 various in the different tribes, and which, by their 

 differences of structure form a leading character in 

 the institution of the Genera or small assortments 

 into which Insects are distributed. 



Among the older writers on Natural History, 

 and even among some of the more modern, several 

 animals are called by the name of Insects, which, 

 in reality belong to a very different tribe of beings, 

 as Snails, several kinds of Worms, and the smaller 

 animals in general. What are termed Animal- 

 cules in modern Natural History are also fre- 

 quently confounded with insects, though in reality 

 belonging to the very different tribe of Vermes or 

 Worm-Like Animals. 



It is not intended at present to enter, with any 

 degree of minuteness, upon the anatomical de- 

 scription and philosophic history of Insects ; since 

 this has long ago been elucidated in almost all its 

 branches by the labours of Swammerdam, Reau- 

 mur, Roesel, and many other authors : to relate 

 therefore what has been so often described may be 

 thought in a great degree unnecessary: yet, on 

 the other hand, it may with equal propriety be 

 observed, that few who have not been particularly 



