296 INSECT TRANSFORMATIONS. 



membrane which covers the more prominently ex- 

 posed 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 from 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, wings, 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 : — nay, they 

 considered the matter as proved, and admired the sup- 

 posed metamorphosis, without giving themselves the 

 trouble of investigating whether it was real or pos- 

 sible. t Accurate observation, founded on the prin- 

 ciples 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." I 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 

 affairs of life, whose bad success may prove a kind of 

 punishment for their reasoning ill, than those which 



* Swammordatn, vol. ii. p. 17. 

 f Ueanmur, vol. i. ]). 350. | Harvey, De Gen. An., Kxer. 44. 



