OF THE ANNULOSA. 411 



ing one piece with it. These three segments in the My- 

 riapoda become more connected together than they are in 

 Crustacea, and when at length they become in a manner 

 compressed into one piece with the three pairs of pedipalpi 

 which are affixed to them, there seems to him reason for 

 supposing that we have before us the head and organs of 

 manducation of a Hexapod insect. This doctrine, how- 

 ever, in as far as it regards the mouth, I cannot consider 

 to be yet established, notwithstanding the ingenuity of 

 some of the arguments by which it is supported. It is 

 particularly hard to discern, for instance, in what respect 

 this opinion, as it affects the second pair of pedipalpi in 

 a Scolopendra, is less objectionable than that of M. Sa- 

 vigny on the same subject. — But we proceed with the 

 more essential part of the theory. — The head, then, being 

 thus formed of three segments in the Crustacea, and be- 

 coming gradually compressed into one, it follows that the 

 body of an insect must be composed of thirteen segments, 

 that is, still allowing five for the thorax and seven for the 

 abdomen. All this Latreille has admirably elucidated, 

 as well as the correspondence of this number of segments 

 with those of Caterpillars and larva? in general. The 

 only objection to it is, the difficulty of accounting for the 

 circumstance of the thorax of Winged insects consisting 

 of no more than three segments. M. Latreille considers 

 that the remaining two become the two first of the abdo- 

 men, — an idea which it is impossible to adopt without 

 giving up his theory altogether. For, in the first place, on 

 looking at any Coleopterous insect we find only seven seg- 

 ments to the abdomen, three to the thorax, and one to the 

 head, eleven in all ; from which it appears that some two 

 Segments which existed in the same insect when a larva 



