350 INSECTA. 



very few, and all from the North, excepted, are strictly peculiar to 

 itj such also is the case with several genera. The eastern conti- 

 nent, 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 re- 

 semblance. 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 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 metamor- 

 phoses; 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 arrange- 

 ments the Crustacea and Arachnides are placed among the Insects, 

 and in that of Linnaeus, the one generally adopted, they are even the 

 last. 



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

 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. The organ of sight in these 

 animals is usually a mere (more or less considerable) assemblage 

 of ocelli resembling granules. 



Certain English naturalists have formed new orders, based upon 

 the wings; I see no necessity, however, for admitting them, that of 

 the Strepsiptera excepted, the name of which appears to me to be 

 erroneous(l), and which I will call Rhipiptera(2). 



In the first order or the Myriapoda, there are more than six feet 

 — twenty-four and upwards — arranged along the whole length of 

 the body, on a suite of annuli, each of which bears one or two pairs, 



( 1 ) Twisted wings. The pai-ts taken for elytra are not so. See this order. 



(2) Wings folded like a fan. 



