ii2 HYMENOPTERA. 



The Gall-Flies (Cynifs). These insects, too, are furnished with a borer, 

 or ovipositor, but of a different character : by its assistance the little Cynips 

 bores the leaves or tender shoots of trees, in which she lays her eggs ; the 

 wounded part, strangely responsive to such a stimulus, swells out into an ex- 

 crescence that is called a gall. The form and the solidity of these vegetable 



FIG. 107. -GALL-FLY. 



productions vary according to the part of the plant which produces them. The 

 leaves, the buds, the petioles, the bark, the roots, all form their different kinds, 

 some of which are useful in the arts. The gall-nut of the oak, for instance, 

 yields a deep black dye, and is employed in making ink. The larvae hatched 

 within these galls find there both board and lodging, till the time arrives for 

 their last change. 



In the second section of the Hymenopterous insects, the fe- 

 males, instead of an ovipositor, are furnished with a sting. This 

 section embraces 



The Ants (Formica), so celebrated for their foresight and their industry. 

 These insects live in societies that are often very numerous, and consist of 

 individuals of three different denominations the males, the females, and the 

 neuters, which last are only females imperfectly developed ; and it is upon 

 them that the work of the colony and the care of the young entirely devolve. 

 The nature and form of the abode of these insects vary in accordance with 

 the instincts of the species : some establish themselves underground, others 

 build edifices of considerable height, surmounted by dome-shaped roofs, others 

 again reside in aged trees, the interior of which they pierce in all directions 

 with their galleries, which., however irregular they may seem, always lead to 

 the nurseries of the establishment. The labours of the industrious neuters 



