1NSECTA. 



241 



same may be said of those vvhicli inhabit the Moluccas, and 

 more eastern islands, those of the Southern Ocean included. 

 Several northern species are found in the mountains of south- 

 ern countries. Those of Africa differ greatly from the oppo- 

 site 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 

 essentially to three. Swammerdam based his on their meta- 

 morphoses ; that of Linnaeus was founded on the presence or 

 absence of wings, their number, consistence, superposition, the 

 nature of their surface, and on the deficiency or presence of a 

 sting. Fabricius had recourse to the parts of the mouth alone. 

 In all these arrangements the Crustacea and Arachnides are 

 placed among the Insects, and in that of Linnaeus, the one ge- 

 nerally adopted, they are even the last. Brisson, however, 

 had separated them, and his class of the Crustacea which he 

 places before that of Insects, comprises all of those animals 

 which have more than six feet, or the Insectes Apiropodes of 

 M. Savigny. Although this order is more natural than that 

 of Linnaeus, it was not followed; and it is only in modern times, 

 that anatomical observations and their rigorously exact appli- 

 cation have brought us to the natural method(l). 



I divide this class into twelve orders: the three first of which; 

 composed of apterous Insects, undergoing no essential change of 

 form or habits, merely subject to simple changes of tegument, 

 or to a kind of a metamorphosis, which increases the number 

 of legs, and that of the annuli of the body ; correspond to the 

 order of the Arachnides antennistes of Lamarck. The organ 

 of sight in these animals is usually a mere (more or less consi- 

 derable) assemblage of simple eyes resembling granules. The 



(1) Cuv., Tabl. Elem. de l'Hist. Nat. des Anim., and Lecons d'Anat. Compar. ; 

 Lamarck, Syst. des Anim. sans Verteb. ; Latr., Precis des Caract. Gener. des In- 

 sect., and Gen. Crust, et Insect. For more minute details, see also the excellent 

 elementary work of Kirby and Spence. 

 Vol. III. 2 F 



