296 INSECT TRANSFORMATIONS. 



membrane which covers th§ more prominently exposed 

 parts, such as the legs, is considerably thicker than the 

 other portions.* Our description will be rendered 

 more intelligible by the preceding figures. 



It will obviously appear fi-om these details, in what 

 manner superficial observations led to the fancy of 

 one insect being on a sudden miraculously metamor- 

 phosed or transmuted into another. Those, indeed, 

 who persuaded themselves that a morsel of tainted 

 beef, or a bit of rotten wood, could, by some inexpli- 

 cable chemistry, grow into limbs, M'ings, eyes, and all 

 the other parts of an insect, with its admirable orga- 

 nization of muscles, nerves, and digestive apparatus, 

 had no difficulty to overcome in believing that the 

 green pulpy mass of a chrysalis could be transmuted 

 into the light airy wings of a butterfly : — iiay, they con- 

 sidered the matter as proved, and admired the sup- 

 posed metamorphosis, without giving themselves the 

 trouble of investigating whether it was real or possi- 

 ble."]" Accurate observation, founded on the princi- 

 ples of the Baconian philosophy, gradually put to 

 flight the reveries of those who (to use the words of 

 Harvey) '■ philosophize by traduction, who are not a 

 whit wiser than the inanimate books through which 

 they come at their ill-digested notions. 'J Yet this 

 distinguished physiologist, though he could so express 

 himself, occasionally struck upon the very sand-bank 

 of which he here warns us to take care; perhaps in 

 consequence of a cause shrewdly and profoundly 

 assigned for philosophical errors by Des Cartes, in 

 his Essay on Method, who says, ' I was always of 

 opinion, that more truth is to be found in those 

 reasonings which men make use of in the common 

 afl^airs of life, whose bad success may prove a kind of 

 punishment for their reasoning ill, than those which 



* Swammerdam, vol. ii, p. 17. 

 ■) Reaumur, vol. i, p. 350. \ Hsivey, De Gen. An., Exer- 44. 



