280 LEPIDOPTERA. 



though unprovided with ordinary limbs, it is not left without 

 the means to extricate itself from its present difficulty. 



The hinder and tapering part of the chrysalis consists of 

 several rings or segments, so joined together as to be capable 

 of moving from side to side upon each other ; and these 

 supply to it the place of hands. By bending together two 

 of these rings near the middle of the body, the chrysalis 

 seizes, in the crevice between them, a portion of the empty 

 caterpillar-skin, and clings to it so as to support itself while 

 it withdraws its tail from the remainder of the skin. 



It is now wholly out of the skin, to which it hangs sus- 

 pended by nipping together the rings of its body ; but, as 

 the chrysalis is much shorter than the caterpillar, it is yet 

 at some distance from the tuft of silk, to which it must 

 climb before it can fix in it the hooks of its hinder extremity. 

 To do this, it extends the rings of its body as far apart as 

 possible, then, bending together two of them above those by 

 which it is suspended, it catches hold of the skin higher up, 

 at the same time letting go below, and, by repeating this 

 process with different rings in succession, it at length reaches 

 the tuft of silk, entangles its hooks among the threads, and 

 then hangs suspended without further risk of falling. It 

 next contrives to dislodge the cast caterpillar-skin by whirl- 

 ing itself around repeatedly, till the old skin is finally loos- 

 ened from its attachment and falls to the ground. The 

 whole of this operation, difficult as it may seem, is performed 

 in the space of a very few minutes, and rarely does the in- 

 sect fail to accomplish it successfully and safely. 



We may see the whole process in the caterpillars of the 

 Archippus butterfly (Danais Archippus of Fabricius), which 

 lives on the common silk-weed or milk-weed (Asdepias 

 Syriaca) in June and July. This caterpillar is cylindrical, 

 with a pair of thread-like black horns on the top of the 

 second segment, and a shorter pair on the eleventh segment, 

 and its body is marked with alternate transverse bands of 

 yellow, black, and white. It comes to its growth in about 



