( xxxix ) 



Mr. Poulton said the experiments appeared to show that 

 the temperature operated at the pupal stage in which the 

 pigment of the perfect insect was being formed, and the 

 stronger colouring seemed to be the effect of retardation in 

 the formation of this pigment. This would be in ac- 

 cordance with his observations as to the colouring of the 

 pupa itself, which was deeper when the formation of it was 

 retarded. 



Dr. F. A. Dixey said that, by the kindness of Mr. Merrifield, 

 he had been enabled to examine the specimens of Vanessa 

 atalanta that afternoon before the meeting. He had at 

 present only seen them by artificial light, but had never- 

 theless been able to satisfy himself that the series was of 

 great interest in view of the conclusions he had previously 

 arrived at with regard to the phylogeny of the Vanessas and 

 allied groups (Trans. Ent. Soc. 1890, pp. 89 etseq.). He might 

 say at once that the characters of those individuals that had 

 been exposed to the greatest cold seemed to him on the whole 

 the most ancestral, as evidence of which he would especially 

 mention the blue centres with which the black submarginal 

 spots of the hind wings were provided in at least two of Mr. 

 Merrifield's " winter " specimens. These, he thought, 

 must be considered as a revival of a character which had 

 belonged to the earliest members of the Vanessid group 

 (Ibid., p. 97 et seq.). Other features in the colouring 

 appeared to him to point in the same direction ; but 

 as to these he must ask to be allowed to reserve his full 

 opinion until he had had an opportunity of studying the 

 specimens more carefully, and with the help of daylight. 

 Mr. Merrifield had pointed out that the minute white spot 

 (D^in the system proposed, Inc. cit.) in the red band of the 

 fore wing of V. atalanta was, in his specimens, often visible 

 on the under side, though absent from the upper. It might 

 be of interest to add that the same was not infrequently the 

 case in instances of the occurrence of the corresponding spot 

 in Pyra)iieis canlui, as also of the next preceding member of 

 the same series, viz. De. When the spots occurred on both 

 surfaces of P. canlui, they were, as in Mr. Merrifield's 

 specimens of V. atalanta, larger and more diffused on the 

 under than on the upper surface (Trans. Ent. Soc, 1890, p. 93 



