}4Q On th$ Caterpillar which 



with the French authorities on the subject, and these 

 only were alluded to, the letter is wholly unsuscepti- 

 ble of the interpretation indulged in by the Doctor. And, 

 certainly, any opinion formed, by any person whatever, 

 must be subject to the controul of the authorities quoted. 

 And, further, how a gentleman could permit himself to 

 say, publicly, that I supposed the Poplar- Caterpillar 

 " would perish in the chrysalis state," because it did 

 not subsequently to this state pass into a butterfly, when 

 the authorities appealed to determined, that if it were 

 spurious, it would become a large fly, is to me resolvable 

 only into that haste which too frequently explains itself by 

 errors. It was at least incumbent on the Doctor to have 

 consulted the authorities. 



In the Doctor's letter he says : " The general curio- 

 sity and alarm, together with the contradictory accounts 

 of experimentalists, though preponderating on the nega- 

 tive scale, made it desirable to know, whether this sus- 

 pected insect would pass the regular metamorphoses of 

 lepidopterous insects, or, as supposed by Dr. Davidge, 

 of Baltimore, would perish in the chrysalis state ; and 

 thus, by an unusual death, seal the apprehension of its 

 venomous nature." 



Whether or not the Poplar- Caterpillar would pass 

 unhurt through the chrysalis state, or possess deleteri- 

 ous properties when in the maturity of the butterfly, so 

 far as my understanding in the matter extends, formed 

 no part of the disputable point. The thing at issue is not, 

 whether the Caterpillar, when raised to its winged state, 

 would possess poisonous qualities, but what its proper- 



