254 HABITATIONS OF INSECTS. 



but to pierce the site of the foundation, and commodious apartments, as if 

 by magic, spring up and surround the germ of her future descendants. I 

 allude to those vegetable excrescences termed galls, some of which re- 

 sembling 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 1 have before noticed, is of such importance 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, like 

 those habitations last described, 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 smooth fleshy consistence, resembling beautiful 

 fruits, for which, indeed, as you have before been told, they are eaten in 

 the Levant : others, beset with spines or clothed with hair, are so much 

 like seed-vessels, that an eminent modern chemist has contended re- 

 specting the Aleppo gall that it is actually a capsule. 1 Some are exactly 

 round ; others like little mushrooms ; others resemble artichokes ; while 

 others again might be taken for flowers ; in short, they are of a hundred 

 different forms, and of all sizes from that of a pin's head to that of a 

 walnut. Nor is their situation on the plant less diversified. Some are 

 found upon the leaf itself; others upon the foot -stalks only; others upon 

 the roots, and others upon the buds.* Some of them cause the branches 

 upon which they grow to shoot out into such singular forms, that the 

 plants producing them were esteemed by the old botanists distinct species. 

 Of this kind is the Rose-willow, which old Gerard figures and describes as 

 " not only making a gallant shew, but also yeelding a most cooling aire in 

 the heat of summer, being set up in houses for the decking of the same." 

 This willow is nothing more than one of the common species, whose twigs, 

 in consequence of the deposition of the egg of a Cynips in their summits, 

 there shoot out into numerous leaves totally different in shape from the 

 other leaves of the tree, and arranged not much unlike those composing 

 the flower of a rose, adhering to the stem even after the others fall off. 

 Sir James Smith mentions a similar lusus on the Provence willows, which 

 at first he took for a tufted lichen. 3 From the same cause the twigs of 

 the common wild rose often shoot out into a beautiful tuft of numerous 

 reddish moss-like fibres wholly dissimilar from the leaves of the plant, 

 deemed by the old naturalists a very valuable medical substance, to which 

 they erroneously gave the name of Bedeguar. None of these variations 

 is accidental or common to several of the tribe, but each peculiar to the 

 galls formed by a single and distinct species of Cynips. 



The Poma Sodomitica, mala insana, or apples of the Dead Sea, beautiful 

 to the eye, but filling the mouth with bitter ashes if tasted, whose exist- 



1 Aikin's Dictionary of Chemistry, i. 455. What have probably been taken by 

 Mr. Aikin for " kernels," in the imperforated nuts, are the cocoons of the inhabitants 

 of these galls in the pupa state, which often extremely resemble the seeds of a 

 capsule, as Reaumur (iii. 429.) has remarked. 



2 Keaum. iii. 417, &c. 3 Introd. to Botany, 349. 



