42 MEMBERS OF INSECTS. 



The Mouth in Insects. 



Following the generalizing views of M. Audouin, in 

 considering the head composed of similar parts to one 

 of the three divisions of the corselet, the mouth will 

 occupy the place of the breast-plate and the two 

 under flanks ; and taking each of these three as com- 

 posed of two pieces, there would be in the mouth, by 

 supposition, six pieces ; and this in fact is the number 

 of pieces found in a great number of species, though 

 not in all ; for, by the law of proportion, when a part 

 is much enlarged, a contiguous part is either very 

 small, or altogether wanting. 



Notwithstanding the mouths of insects are thus 

 composed of a determinate number of pieces, their 

 structure both appears to be, and is, very different, 

 for example, in a bug, a butterfly, a bee, and a 

 beetle, owing to the difference of form, as well as to 

 the difference of junction in the several pieces. 



M. Lamarck, who seems first to have had a glimpse 

 of the general uniformity in the number of pieces in 

 the mouth of all insects, at once leapt to the singular 

 and untenable conclusion, that bugs, through process 

 of time, got rid of the joinings that made their mouths 

 into a tube, and successively improved themselves 

 into beetles with good moveable jaws. M. Savigny, 

 reversing this process, thinks the jaws of the beetle 

 degenerated into the suckers of the butterfly and the 

 bee. 



Many of our English naturalists, from being far 

 behind in logic and generalizing, and therefore in- 

 competent to take advantage of Continental researches, 

 so admirable when they are stript of theory, forthwith 

 conclude, that all insects, without free, moveable jaws, 

 or having any of the six pieces wanting, have imper- 

 fect mouths. One English naturalist in particular, 

 by a gross misconception of Savigny's meaning, re- 



