446 HABITATIONS OF INSECTS. 



ing vacuity of the hole ; taking down the pellets, which 

 are very conveniently at hand, and placing them in it 

 until the entrance is filled 1 . Latreille informs us, that 

 a nearly similar tunnel, but composed of grains of earth, 

 is built at the entrance of its cell by a bee of his family 

 of pioneers**. 



Under this head, too, may be most conveniently ar- 

 ranged the very singular habitations of the larvaa of the 

 Linnsean genus Cynips, the gall-fly, though they can 

 with no propriety be said to be constructed by the mo- 

 ther, who, provided with an instrument as potent as an 

 enchanter's wand, has but lo pierce the site of the foun- 

 dation, and commodious apartments, as if by magic, 

 spring up and surround the germe of her future de- 

 scendants. I allude to those vegetable excrescencies 

 termed galls, some of which resembling beautiful berries 

 and others apples, you must have frequently observed 

 on the leaves of the oak, and of which one species, the 

 Aleppo gall, as I have before noticed, is of such import- 

 ance in the ingenious art " de peindre la parole et de 

 parler aux yeux*" All these tumours owe their origin to 

 the deposition of an egg in the substance out of which 

 they grow. This egg, too small almost for perception, 

 the parent insect, a little four-winged fly, introduces into 

 a puncture made by her curious spiral sting, and in a 

 few hours it becomes surrounded with a fleshy chamber, 

 which not only serves its young for shelter and defence, 

 but also for food ; the future little hermit feeding upon 

 its interior and there undergoing its metamorphosis. 

 Nothing can be more varied than these habitations. 

 Some are of a globular form, a bright red colour, and 



* Reaum. vi. 251-7. t. xxvi. /.I. b Latr. Fourmis, 419. 



c See above, p. 317. 



