Gout) 
III. On the phylogenetic significance of the variations 
produced by difference of temperature in Vanessa 
atalanta. An Appendix to the preceding paper. 
By Dr. Freprrick Aucustus Drxry, M.A., M.D., 
Fellow of Wadham College, Oxford. 
[Read February 22nd, 1893. ] 
Mr. Merrirretp has kindly invited me to express my 
opinion as to the bearing of the variations produced by 
differences of temperature in his specimens of Vanessa 
atalanta on the question of the race-history of the 
Vanessas. Iam strongly disposed to think that further 
data are necessary before very much light can be thrown 
on the subject from this source; nevertheless, certain 
conclusions seem possible from the remarkable series 
so carefully reared by Mr. Merrifield under accurately 
recorded conditions of temperature, and perhaps a brief 
note on the subject may be not devoid of interest, even 
at the present stage of the enquiry. 
For the purposes of this note, I divide Mr. Merrifield’s 
specimens of V. atalanta that I have seen as follows :— 
A. Reared from pupe at a temperature of 80° to 
90° F. 10 specimens. (Fig. 3). 
B. Reared at ordinary temperatures. 10 specimens. 
C. Reared from pup at about 54° to 56°. 10 speci- 
mens. (Fig. 4). 
D. Reared from pupe at 45°. 7 specimens. (Figs. 5 
and 5a). 
Both A and D exhibit features which appear to be 
ancestral, together with other features which would seem 
to be the direct result of temperature conditions, or at 
least to have no assignable phylogenetic import. Al- 
though both A and D show indications of reversion, the 
ancestral marks are different in the two cases. The 
specimens grouped as C do not differ very greatly from 
the normal, but are in most respects intermediate be- 
tween B and D. 
TRANS. ENT. SOC. LOND. 1898.—part I. (MARCH.) 
