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 re-visited 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 Vanessce. 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 Vanessce 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 pupae. 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. 



