56 STATES OF INSECTS. 



erroneously mistaken for the period of their existence 3 ." 

 This has been Dr. Herald's, grand error; he mistook the 

 commencement of the appearance of the organs of the 

 butterfly for that of their existence^ and yet the early ap- 

 pearance of the sexual organs ought to have led him to 

 a conelusion the reverse of that which he has adopted. 



Dr. Virey has observed with great truth — that " Every 

 being has a peculiar and unique nature, which would be 

 impossible if the body was composed of parts made at 

 several intervals, and without a uniform power that acts 

 by concert b :" and every Physiologist acquainted with 

 the history of insects that undergo a complete metamor- 

 phosis will allow, that their developments and acquisition 

 of new parts and organs take place according to a law 

 which regulates the number, kind, and times of them, 

 differing in different species, and which has had an in- 

 variable operation, since the first creation, upon every 

 sound individual that has been produced into the world. 



In consequence of this law, one species changes its 

 skin only four times, and another^*? or six ; — in some 

 cases the first skins shall be covered or bristled with 

 hairs or spines, and the last be naked and without arms ; 

 -—that which forms the case of the pupae shall differ in 

 form and substance from the preceding skins, varying in 

 both respects in different species; and finally the butterfly 

 shall invariably follow, when no other change but the 



a CEuv. v. 279. " II n'est pas exact de dire que le coeur, la tete, et 

 la moelle epiniere, sont formes les premiers dans les foetus des ani- 

 maux a sang rouge et vertebres," says Dr. Virey; " mais il faut dire 

 seulement que tel est l'ordre dans lequel ces organes commencent a 

 devenir visibles." N. Diet. d'Hist. Nat, x. 1967 



b Ibid, ID'S. 



