THE LEPIDOPTERA. 



9r 



their growth really form a most important part of the phenomena 

 of evolution, for some very necessary alterations in the internal 

 structures progress especially during the last stage of quiet retire- 

 ment which accompanies the final change of skin before the 

 commencement of the chrysalis state. 



Although several broods of caterpillars are born in a year 

 in such species as AntJiocJiaris belia and Vanessa prorsa, yet 



CHRYSALIDES SLUNG AND SUSPENDED. 



the successive larvae present no distinctions in their external 

 ornamentation, but the perfect insects which are metamorphosed 

 from these similar larvae do differ very materially. Yet the 

 butterflies of Vanessa lo, a species closely allied to Vanessa 

 prorsa, are always the same, notwithstanding there are successive 

 broods of them in the year. 



This variation in the colouring and ornamentation of the 

 butterflies of successive broods is most interesting, especially 

 when it is considered in relation to the opposite state of things 

 so common in some species of moths, whose generations of 

 caterpillars differ, the perfect insects remaining unaltered. The 



