Insects. 4813 



first brood, because there were no leaves on the trees to nourish one earlier ; and it 

 now only remains for some one to find a second brood this year to establish that the 

 species is double-brooded. The condition of the female I caught, taken, be it noticed, 

 at the time some of the larvse were full-fed, shows that it could have belonged to no 

 "summer" brood. The larvae I found will be butterflies in August. The second 

 brood of larvae therefore must be looked for in August, and I hope whoever finds will 

 inform us. — J. W. Douglas ; Lee, July 12, 1855. 



Gonepteryx Rhamni double-brooded? — Before touching upon this vexaia qucestio, 

 will you allow me to intrude upon you the answers I have received from my friend Pro- 

 fessor Zeller to the first four somewhat similar questions I propounded at page 150 of 

 the ' Entomologist's Annual :*-— 



" 1. Papilio Machaon. The Machaon which you saw on the 25th of May at 'the 

 Forester's house had that month escaped from the pupa, which had wintered, and 

 of which the larva had lived in August and September (probably on Athamanta Oreose- 

 linum). Its subsequent appearance takes place in July and August, from the eggs laid 

 in June. Two broods in the year are in our neighbourhood past all doubt, and 

 there appears no reason why in England it should only be single-brooded. 



" 2. Colias Hyale flies at the end of May and beginning of June, and has then 

 escaped from pupa? of which the larvae, of various sizes, had wintered. Its later 

 appearance is from July to late in September. The latter specimens are probably all 

 descendants of the Hyale which fly in May ; since from eggs which I collected in 

 July, and the larvae from which I fed with their favourite plant, Trifolium repens, I 

 obtained a male butterfly on the 3rd of September. The females which come out at 

 that time certainly lay eggs, from which iu about ten days the larvae proceed, which 

 on the approach of frost seek their winter-quarters. Thus this species is certainly 

 double-brooded. 



" 3. Melitaea Selene appears with us in August, not scarce, in the same places 

 which it frequents in May and June. Euphrosyne is too scarce here for me to have 

 observed it twice a-year; but I doubt not that where it occurs abundantly it is 

 double-brooded. 



"4. Argynnis Lathonia, quite certainly double-brooded ; flying in June from larvae 

 that have wintered. The summer brood appears in August, and continues till late in 

 September. As in Hyale, it is much more plentiful than the spring brood ; whilst the 

 reverse is the case with Selene." 



In the two first of these instance we have the insect traced through its various stages 

 of egg, larva, pupa and imago, and, insects all being subject to these metamorphoses, 

 that seems the rational mode of proceeding in an argument on such a subject. Now, 

 to apply this to Gonepteryx Rhamni, do not the hybernated females lay eggs in the 

 spring?— do not these eggs produce larvae which feed up in May, and furnish the per- 

 fect insect in June?— do not these latter lay eggs which produce larvae that feed up in 

 July ? — and do not these larvae furnish the autumnal and most plentiful brood of the 

 imago of G. Rhamni? I pause for an answer to these inquiries. It seems to me the 

 height of absurdity that we know that Nepticula anomalella and N. marginicolella are 

 double-brooded, and that we have good grounds for believing that Nepticula angulifas- 

 ciella and N. viscerella (though respectively feeding on the same plants, rose and elm) 

 are single-brooded, and yet no entomologist exists in Britain sufficiently observant to 

 have noticed the transformations of G. Rhamni, the double-broodedness of which was 



xiii. 2 o 



