104 THE BUTTERFLY VIVARIUM. 



reference to the loop which is best calculated 'to 

 afford an even balance, and then, like the larva of 

 the "White Butterfly, it holds itself still, and in 

 a straight position, to await the impending trans- 

 formation. Sometimes, in spite of the beautiful 

 accuracy with which it performs its work, the 

 head gets entangled in passing through the loop 

 formed of forty or fifty threads, which causes great 

 labour to the unfortunate larva. Generally, how- 

 ever, after repeated efforts, it manages to extricate 

 itself and complete its preparation ; but in the con- 

 trary case, it always perishes without the transfor- 

 mation being accomplished. 



A third method of forming this loop is practised 

 by the short, "Wood Louse-formed Caterpillars of the 

 pretty little Butterflies of the Thecla family. These 

 Caterpillars, the shape of which may be judged of 

 by that of one of the Argus family, in Plate II. No. 7, 

 place the loop just over the head, instead of in the 

 front of it like the larvse of the Swallow-tail, and 

 afterwards force the body forward till the loop is 

 nearly in the middle. 



The larvse of another class of our native Butter- 

 flies, instead of securing themselves by means of 

 a loop round the centre of the body, suspend them- 

 selves by a kind of web, which attaches the tail to 



