1'ltUFACE. V 



Linnaeus to his class of Insects ; he however made some necess- 

 ary ameliorations, which have since served as the foundation 

 of other systems. He distinguishes Insects, in the first place, 

 from other invertebrate animals, by much more rigorous cha- 

 racters than those previously employed, viz. a knotted medul- 

 lary spinal marrow, and articulated limbs. Linnaius termi- 

 nates his class of Insects with those which are apterous, 

 although most of them, such as the Crustacea and the Jlra- 

 neides, with respect to their organization, are the most per- 

 fect of their class or are the most closely approximated to the 

 Mollusca. His method, in this respect, is then exactly the 

 inverse of the natural system, and by transporting the Crus- 

 tacea to the head of the class, and by placing almost all the 

 Aptera of Linnaeus directly after them, Cuvier rectified the 

 method in a point where the series was in direct opposition to 

 the scale formed by Nature. 



In his Legons d' Anatomic Comparce, the class of Insects, 

 from which he now separates the Crustacea, is divided into 

 nine orders, founded on the nature and functions of the or- 

 gans of manducation, the presence or absence of wings, their 

 number, consistence, and the manner in which they are reti- 

 culated. It is in fact a union of the system of Fabricius with 

 that of Linnseus perfected. 



The divisions made by our savant in his first order, that of 

 the Gnathaptera, are nearly similar to those I had established 

 in a Memoir presented to the Societe Philomatique, April 

 1795, and in my Precis des Carac teres Gmeriques des In- 

 sect es{\). 



M. de Lamarck, whose name is so dear to the friends of 

 natural science, has ably profited by these various labours. 

 His systematic arrangement of the Linnsean Aptera appears 

 to us to be that which approaches nearest to the natural order, 

 and, with some modifications of which we are about to speak, 

 is the one we have followed. 



(1) 1 there divided the Aptera of Linnceus into seven orders: 1. The Suctoiua. 

 2. The Thi8anouiu. 3. The Takasita. 4. The Acephala (Arac/mldca pal- 

 pistes,Lm\.)- 5. The Entomosthaca 6. The Crustacea. 7 The Miiuajoda. 



