64 Mr. F. Merrifield on effects of temperature 
which have almost disappeared, and the breadth and conspicuous- 
ness of the coppery band on the hind wings, which ceases to be 
serrated, though the coppery scales are often prolonged along the 
nervures from the band towards the base of the wings. I tried a 
further experiment with some iced at 33° for 9 or 10 weeks, which 
I consider sufficiently proves that the dusky suffusion is, at least 
to some extent, the effect of a moderately low temperature extend- 
ing over some of the later pupal stages. Six of those iced for 
about 10 weeks were transferred at once to a temperature of 90° ; 
these all emerged in from 5 to 6 days, and it will be seen that they 
have most of the features of those that were never at a lower tem- 
perature than 80° to 90°, and especially the suffusion of the bases 
of the fore wings with duskiness, and the reduced size of the cop- 
pery band on the hind wings. The contrast in colouring between 
the last two lots, the only difference between them in treatment 
being that, both having been long iced, one lot emerged at 55° 
while the other emerged at 90°, is noticeable. 
The only individuals which seemed at all injured by the tem- 
perature applied were those at 47°, and those which after long 
icing were placed at about 55°. Mere icing for 10 weeks did not 
seem at all injurious. 
I will summarise the results as follows :— 
I. At 80°—90°. Representing a very hot continental 
summer temperature (Figs. 1 and la). Emerged in 6 
days. Spots large, not sharply defined ; dusky suffusion 
of fore wings. 
II. At about 70° (English summer temperature). 
Emerged in 11 to 15 days. Spots smaller, copper 
colour more vivid, black more intense. 
IIl. At about 56° to 58° (rather cool summer or 
late spring temperature). Hmerged in 22 to 23 days. 
Copper colour still more vivid; copper band on hind 
wings broader. . 
IV. At about 45° (temperature of cold spring). 
Emerged in 57 to 59 days. Effects intensified. 
V. At 38° for 10 weeks, then at 55° for 5 weeks (winter 
and spring temperatures) (Figs. 2 and 2a). Extreme 
effects produced, especially in smallness of spots and 
breadth of the coppery band on hind wings. 
VI. At 38°, then 90° for 6 days (winter, immediately 
followed by very hot summer). Re-appearance of dusky 
suffusion and of narrowness of copper band on hind 
wings. 
