THE TOHTOISE-SHELL BUTTERFLY. SOS 



Extraordinary power of instinct. 



jacent places. As they fly very low, and fre- 

 quently settle, they are easily caught. The ca- 

 terpillars are generally at their full growth about 

 the last week in April: when this takes place 

 they suspend themselves by the tail to change 

 into chrysalids, in which state they remain four- 

 teen days. Their mode of suspension is a singu- 

 lar instance of the extraordinary power of in- 

 stinct. They first draw two or three small blades 

 of grass across towards their top, and fasten them 

 together by means of their silk : then hang them- 

 selves beneath the centre of these, each having 

 his own little canopy. By this means they are 

 not only hidden from the sight of birds, but de- 

 fended in a great measure from the damage they 

 might otherwise sustain from windy and boiste- 

 rous weather. They feed on the devil's-bit sca- 

 bious and on various kinds of the marsh grasses; 

 eating only the opening leaves as they come up, 

 which renders them sometimes difficult to find. 

 This they do also only while the sun shines; for 

 if, in the very act, the sun becomes hidden be- 

 hind by a cloud, they immediately cease, but, on 

 the return of the sun-beams, they recommence 

 their operations with great voracity. 



The upper wings of the nettle tortoise-shell 

 butterfly, which is one of the most beautiful and 

 Common of the British butterflies, are red, and 

 marked with alternate bands of black and pale 

 orange; below these are three black spots, the 

 inner one of which is square; and near the ex* 



