82 TRANSFORMATIONS OF INSECTS. 
very small; some of them may be seen towards the end of 
April or the beginning of May, when Nature has awakened 
from her long sleep, and the leaves are beautiful from their 
freshness. They play around the nettles under the shade of 
the damp underwood. Their wings look new and unworn, for 
their texture resembles velvet, and they are of a bright fawn 
colour, being also ornamented with wandering black lines, which 
give the common name to the insect of the “carte geographique.” 
If the same spots are revisited during the month of June, none 
of the pretty little butterflies can be seen, but the nettle leaves 
are covered here and there with little black caterpillars, which 
have white dots, and fine branching spines. These are the 
offspring of the pretty April butterflies. When the caterpillars 
have attained their full growth they separate, and each, after 
fastening itself, becomes a grey chrysalis, having the angular 
form, like those of all Vanesse. It is now the month of June, 
and the temperature of the air is high, so that the development 
and the metamorphoses are rapid. A fortnight passes, and the 
little “cartes geographiques” burst from the chrysalis state. 
Now this second generation differs materially, so far as colouring 
is concerned, from the first which produced it. The wings of the 
July butterflies are black, and are scratched with whitish lines. 
But this is not all. The Vanesse@ with the black wings 
lay their eggs, and little caterpillars are hatched, in August and 
September. These devour the favourite nettles, and resemble 
those which did the same thing in June. Like the others, 
these autumnal caterpillars hang themselves up, and are meta- 
morphosed into pupe. If the autumn is fortunately a prolonged 
summer, some butterflies will escape from the chrysalis condition 
in October. Strange to say, their wings have neither the black 
colours of the July butterflies, nor the fawn tint of the April 
brood, but an intermediate ornamentation. This late meta- 
morphosis is rare, but it can be produced artificially by keeping 
the chrysalides in a warm place. Most of the chrysalides, and 
sometimes all of them, live in this state through the winter, 
and are metamorphosed into the true “cartes geographiques” 
during the spring, and the butterflies are then tinted with fawn 
colour. 
