326 THE NETTLE TORTOISE-SHELL BUTTERFLY. 



black spots, the inner one of which is square ; and 

 near the extremity of their upper parts is a white 

 stripe. The lower wings are also red, marked with 

 a large black patch at the base. The margins of all 

 of them are black, with blue spots. 



These Butterflies are produced from their chry- 

 salids, and first make their appearance in a winged 

 state about the month of April. They are short- 

 lived, laying their eggs in the beginning of the fol- 

 lowing month, in great numbers, on the uppermost 

 stalks of the nettles, and dying very shortly after- 

 wards. 



The eggs adhere by means of the glutinous mois- 

 ture with which they are covered when first pro- 

 truded. About the middle of the month, the young 

 caterpillars may be seen of a light green colour on 

 the nettle-tops, enclosed in a web that covers the 

 whole upper part of the plant; and in this they all 

 herd together. They soon cast their first skin, when 

 they always remove to a fresh place, leaving their 

 old coverings hanging to the web. Here, at a little 

 distance from their former habitation, they form a 

 new coloiw. In their third skin they make another 

 remove, but still keep together in a web. On 

 changing this they also change their colour and be- 

 come black ; and as they have now increased too 

 much in size to live in one society, they separate 

 into companies. Jn their sixth or last skin they 

 entirely separate ; and in this state they often make 

 such ravages among the nettles as to leave nothing 

 but the stalks and fibres. Sometimes they are seen 

 so numerous as to cover all the tops, and six or se- 



