experiments on some Lejndoptera. 159 



by Mr, Stainton in his ' Manual.' Broadly speaking, 

 the effects produced under B and C conditions are ver}- 

 similar, and those under D and E are similar, but in 

 each direction there is a marked intensification of the 

 chief characteristics in both C and E, the larvae of which 

 were forced. 



Explanation of Plates IV. & V. 



I 



PLATE IV. 

 ii". autumnaria. 

 Figs. 1, 2. Ordinary temi^eratiire as larvae, and as pnpa?. 

 (? and ? . 

 3, 4. Ordinary temperature as larvae, forced as pupif, 



$ and $ . 

 5, G. Ordinary temperature as larvie, cooled as pupae, 



^ and 5 . 

 7, 8. Forced as larvae, and as pupae, ^ and J . 

 9, 10. Forced as larvae, cooled as pupae, $ and J . 



All the specimens figured are from the same parents. 



PLATE V. 

 8. ilhistraria. 

 Figs. 1, 2. Summer pupae, not iced, ^ and J . 



3, 4. Summer pupae, iced 16 weeks, ^ and $ . The 

 specimens figured 1, 2, 3 and 4 are from the 

 same parents. Fig. 3, though a small part of 

 one posterior wing is imperfectly developed, is 

 selected because it is the best illustration of 

 darkness and change of markings combined. 

 There are other specimens more extreme in both 

 particulars. 

 5. Autumn pupa, forced 17 days, $ . 

 0. Autumn pupa, forced 34 days, J . 

 7, 8. Autumn pupae, not forced, spring emergence, 

 (J and $ . Tlie specimens figured f), 6, 7 and 8 

 are from the same parents. 

 9. Autumn pupa, forced 59 days, $ . 

 10. Autumn piipa, warmed 60 days, also wintered 35 

 days, 5 . The specimens figured 9 and 10 are 

 from the same parents. 

 11, 12. An ordinary form of the very variable summer 



emergence, <? and ? . 

 13, 14, Rather dark examples of the ordinary spring 

 emergence, ^ and $ . 



