324 



Professor E. B. Poulton on colour-relation 



Dates in 1893. 



Black twigs of 

 Turkish oak. 



Deep blue paper 

 si:)ills. 



III. 



Dark purplLsh-browii 



glos.sy twigs probably 



of bircli. 



IV. 



White-sijotted 



purjjlish-brown twigs 



of birch. 



July 15. 15 on twiijs. 



(W. Holland.) very black.' 



All 10 on spills, 2 

 on green. AH very 

 dark. 



14 on twigs, 1 

 on green. All very 

 dark purplish- 

 brown. 



12 on twigs, 4 

 on green. Colour 

 darkish brown but 

 distinctly paler 

 than III. 



July 18. 

 (W. Holland.) 



July 23. 

 (W. Holland.) 



July 27. 

 Careful com- 

 parison 

 (E. B. P.) 



As befort 



As befort 



As before. 



As before. 



As before. 



Some mature 

 and spinning up. 



Some pupating. 6 larvre remain, 

 All black, but one ' nearly mature. All 

 has very faint > wr/yclark purplish, 

 traces of green on j almost black, as 

 sides anteriorly, on many pievious 

 These 1 a r v ib occasions. 

 blacker and less 

 purple than those 

 with blue spills 

 (ID- 



July 28. I 8 larvai still 5 still feeding. 

 (W. Holland.) feeding. All on ; 4 on spills, 1 on 

 twigs. leaf 



1 Aug. 3. 

 I (W. Holland.) 



(Aug. 8. 

 W. Holland.) 



(July 31.) A 

 typical larva 

 painted ; shown in 

 Plate XVI, fig. 1. 

 (Aug. 4.) Re"- fed. 



Re-fed. . One or 

 two still feeding. 



As before. 



All a very uniform 

 dark purplish- 

 brown, almost 

 black, but not so 

 much so as those 

 with the blue 

 spills. 



As before. 



All dark greyish- 

 brown and very 

 uniform. 



9 still feeding : 12 still feeding : 

 all on twigs, all on twigs. 

 (July 30.) A,(Jtily 30.) A 

 ty]ncal larvatypical larva 

 painted ; shown in painted ; shown in 

 Plate XVI, fig. 3. Plate XVI, fig. 4. 



5 still feeding. 

 4 on twigs, 1 on 

 green. 



As before. All 5 

 on twigs. 



6 feeding, 

 on twigs. 



All 



5 feeding : all 

 on twigs. Colour 

 as before. (Aug. 

 19.) 3 still feed- 

 ing. 



