SUSPENSION OF PUP^. 279 



after being removed from their suspensories, also roll 

 about and manifest great uneasiness.* 



But this is only one mode by which chrysalides 

 are suspended; for nature, rich in variety, has taught 

 others to employ a different mechanism, and consid- 

 erably more complicated, not only hxing themselves 

 by the tail, but throwing around their body a girdle 

 of silk, which binds it firmly to the spot selected, and 

 frequently in a horizontal position. Amongst those, 

 the caterpillars of the pretty butterflies called by col- 

 lectors hairstreaks {TheclcZy Fabr.), are remarkable, 

 both for their resemblance in shape to the common 

 woodlouse (Oniscus), and for their singular proceed- 

 ings. In order to construct a silken cincture around the 

 middle of its body, after it has secured itself at the tail, 

 the Thecla draws back its head, and pushing out its 

 spinneret on one side, forms an arched thread by pass- 

 ing it over to the other side. It then insinuates its 

 head under this thread, and pressing the fore part of its 

 body down as closely as possible, it contrives to place 

 the girth over its middle. This circumstance is the more 

 remarkable when it is considered that the silk is so 

 fine as scarcely to be distinguishable to the eye, and 

 that the back of the caterpillar over which it has to pass 

 is thickly bestudded with spines. The caterpillars, in- 

 deed, of this whole family {Lyccenceidce, Leach), 

 which includes our splendid blue and copper butter- 

 flies, seem to follow the same process, repeating it 

 from thirty to fifty times, in order to strengthen the 

 band. As the caterpillars of the family just men- 

 tioned are but seldom found, those who are desirous 

 of observing the formation of the cincture of a chry- 

 salis may readily gratify their curiosity by watching 

 a brood of any of the native white butterflies, as 

 those of the cabbage or of the hawthorn (Pieris 

 Cratcegi, Stephens). A caterpillar of this kind, 



* Bonnet, CEuvres, vol. ii, p. 109. 



