JNTRODUCTIOX. 7 



which, emerging in the middle of summer, retire early into 

 some hiding-place in which they remain through the winter, 

 coming out in the spring to fly about, to pair, and deposit 

 eggs. These specimens, when the spring is late, may be found 

 on the wing far into the summer. But in the vast majority of 

 cases the business of reproducing the species is attended to 

 within a few days, or, at furthest, weeks, of emergence, and 

 then the insects become worn in appearance and speedily die. 

 None are more prompt to attend to this important duty than 

 those species which are devoid of means of taking subsistence. 



Though all species of Lepidoptera pass through the series 

 of changes just mentioned, there are a few which do not 

 seem to reach the same perfect condition as the rest. This 

 occurs mainly in the female sex, the individuals of which, in 

 some species, have no effective wings, or even no wings at all, 

 and in a few species no legs nor antennje, so that the unfor- 

 tunates must remain in the cases in which they previously 

 lived and assumed the pupa state, and there lay their eggs 

 and die. In this last instance the females usually possess 

 the power of laying fertile eggs without the intervention of 

 the male, and in one species at least this extraordinary 

 method of reproduction (which is called Parthenogenesis) is 

 so complete that, although the female is plentiful, the male 

 is totally unknown. In those species which have wingless 

 (ciptcrmts) females, not living in cases, but well provided with 

 legs, this power does not seem to be present ; yet it appears 

 capriciously and most inexplicably now and then in winged 

 species. 



It would be easy to write a volume upon the variations to 

 which perfect insects, and even their larvas and pupte, are 

 liable, the conditions under which these variations occur, the 

 habits of the creatures, and their natural history in all stages ; 

 but these are subjects too large to enter upon here, and it is 

 the hope and desire of the writer to furnish some such infor- 

 mation in connection with each species separately. The 

 subjects of collfCtiug in the perfect state, as well as in the 



