172 NATURAL HISTORY. [cH. IX. 



demand which exists for it ; and the only trouble 

 required in gathering this substance consists in break- 

 ing down the branches and carrying them to market. 



The shell-lac is used by the natives in making or- 

 naments, rings, necklaces, and bracelets ; when im- 

 pregnated with cinnabar it forms sealing-wax, or, as 

 the Dutch call it, segel-lak (seal-lac). When heated 

 and mixed with a black powder, it may be spread 

 on a box or other article for the purpose of japanning 

 it. It also enters into the composition of various 

 varnishes. It affords likewise a beautiful red colour 

 by throwing the insect into water. 



Of the insects which are common to various parts 

 of Europe, it may be said that the cocci fix them- 

 selves to such plants as are hardy enough to pass the 

 winter through. " All that I know," says Reaumur, 

 " require a plant capable of nourishing them for one 

 year, the natural term of the life of these insects." 

 While young they attach themselves to the leaves, 

 and as these wither away, descend to the branches, 

 where they adhere during the winter. As spring 

 returns, they become fecundated, and prepare to 

 perpetuate their species. One of these insects, 

 which sucks the juice of the peach, is boat-shaped ; 

 its skin, which is all that can be seen, is exactly like 

 the fine bark of the cherry-tree. On looking at the 

 peach, some of these gall-insects may be observed 

 dry and dead, others alive, though immoveable ; 

 those on the old branches are for the most part of 

 the former, those in the new shoots of the latter class. 

 They may farther be known by the colour of the 

 latter being more brilliant than that of the former ; 

 and also by the dead ones being easily pushed off 

 with the finger or a penknife, while the live insect 

 adheres : a more violent push kills them ; and they 

 yield a thick liquid substance, similar to that which 

 is produced by crushing any other species of living 

 insect. The spot from whence the coccus has been 

 removed is covered with a downy cotton, which 



