Vlll PREFACE. 



in a secondary light. My series of Orders relative to the 

 winged Insects is, consequently, nearly similar to that of 

 Linnaeus. 



Fabricius, Cuvier, Lamarck, Clairville and Dumeril, con- 

 sidering the difference of the functions of the parts of the 

 mouth of primary consequence, have arranged those divisions 

 otherwise. 



In accordance with the plan of M. Cuvier, I have reduced 

 the number of families which I established in my previous 

 works, and have converted into subgenera the numerous divi- 

 sions that have been made of the genera of Linnaeus, notwith- 

 standing their characters may otherwise be very distinct. 



Such also was the intention of Gmelin in his edition of the 

 Systejna A\iturse. This method is simple, historical and 

 convenient, as it enables the student to proportion his instruc- 

 tion to his age, his capacity, or to the end he has in view. 



All my groups are founded on a comparative examination 

 of all the parts of the animals I wish to describe, and on the 

 observation of their habits. Most Naturalists stray from the 

 natural system by being too exclusive in their considerations. 

 To the facts collected by Reaumur, Roesel, De Geer, Bonnet, 

 the Hubers, &c. respecting the instinct of Insects, I have 

 added several ascertained by myself, some of which were 

 hitherto unknown. M. Cuvier has added to them an extract 

 of his anatomical observations(l); he has even devoted himself 

 to fresh researches, among which I will mention those whose 

 object was the organization of the Lirauli, a very singular 

 genus of the Crustacea. 



Being necessarily restricted in the description of species, 

 I have always selected for that purpose the most interesting 

 and common ones, and particularly those mentioned by M. 

 Cuvier in his Tableau Elementaire de PHistoire Naturelle 

 des Animaux. 



LATREILLE. 



(I) Those added to the present edition are from Messrs Leon Dufour, Marcel 

 de Serres, Straus, Audouin and Milne Edwards, 



