(ECONOMY 
86 
other things neceffary to fatisfy their natural 
wants ; for them other, foon after fhe has laid her 
eggs, dyes, and were fhe to live fhe would not 
have it in her power to take care of her young. 
Butterflies , moths, fome beetles , wevils , 
bugs , cuckow-fpit infers, gall-inf efts , tree 
bugs , &c. lay their eggs, on the leaves of 
plants, and every different tribe choofes its 
own fpecies of plant*. Nay there is fcarce any 
plant, which does not afford nourifhment to 
fome infeft ; and ftill more, there is fcarcely 
any part of a plant, which is not preferred by 
fome of them* Thus one infeft feeds upon the 
flower * another upon the trunk ; another up- 
on the root ; and another upon the leaves. But 
we cannot help wondering particularly, when 
we fee how the leaves of fome trees, and plants, 
after eggs have been let into them, grow into 
galls; and form dwellings, as it were, for 
the young ones, where they may conveniently 
live. Thus when th z gall-inf eft called cynips , 
Fn. 947. has fixed her eggs in the leaves of 
an oak, the wound of the leaf fwells, and a 
knob like an apple arifes, which includes and 
nourifhes the embryo. 
* Vid. Syft. Nat. Edit. 10. Fauna Suecica ; and Hofpita 
Xnfe&orum Flora Aman. Academ. vol. 3. 
When 
