10 INSECT MANUFACTURES. 



where they may quietly undergo their changes 

 until they become perfect winged insects. 



The astonishing task of supplying silk for the 

 whole civilized world is performed almost without 

 exception by the common silkworm, or caterpil- 

 lar of the mulberry-tree moth. 

 But it must not be supposed that 

 this is the only silk -producing 

 insect. On the contrary, all the 

 caterpillars of butterflies and moths 

 have the power of spinning a 

 certain quantity of silken thread, 

 however small, and however in- 

 ferior to that of the silkworm* 

 properly so called. It is very com- 

 mon in gardens to see numbers of 

 caterpillars dangling by their silken 

 threads from the young branches 

 of fruit-trees. In this way they let 

 themselves down, or break their fall 

 if blown off by the wind, or other- 



SILKEK THREAD. 



tree. And in the case of some caterpillars 



