A. One of the points detached.
B. Section of the base.
C, D. Cynips emerging.
And now the prosaic entomologist proceeds to supplant fact for fancy. This gall-fly is a sort of cousin to the wasps, but what we would call its sting is more than a mere sting. Like a sting, it seems to puncture the bark or leaf, and at the same time probably to inject its drop of venom; but at the same time it conveys to the depths of the wound a tiny egg, or perhaps a host of them. One gall-fly is thus a magician in chemistry, at least, for no sooner are these eggs deposited than the wounded branch begins to swell and form a cellular growth or tumor about them, the character of this abnormal growth depending upon the peculiar charm of the venomous touch—to one a tiny coral globe, to another a cluster of spines, to another a curved horn, and to our cynips of the white or scrub oak a peculiar globular, spongy growth which completely envelops the stem, sometimes to the size of a small apple. In its prime it is a beautiful object, with its fibrous, glistening texture studded with pink points. But this condition lasts but a few days, when the entire mass becomes brownish and woolly, which fact has given this insect the common name of "wool-sower."
And now we must lose no time if we would follow its history to its complete cycle. If we put one of these faded sponges in a tight-closed box, we shall in a few days learn the secret of its being. For this singular mimic fruit which has sprung at the behest of the gall-fly, like other fruits, has its seeds—seeds which are animated with peculiar life, and which sprout in a way we would hardly expect. Within a fortnight after gathering, perhaps, we find our box swarming with tiny, black flies, while if we dissect the sponge we find its long-beaked seeds entirely empty, and each with a clean round hole gnawed through its shell, explaining this host of gall-flies, all similar to the parent of a few weeks since, and all bent on the same mischief when you shall let them loose at the window.
The beautiful sponge of the sweet-brier has been called into being by exactly similar means, and its hard, woody centre is packed full of cells, at first each with its tiny egg, and then with its plump larva, followed by the chrysalis, and at length by the emergence of the full-fledged Cynips rosæ.
This sponge-gall of the rose is commonly known as the Bedegnar, and, like all other members of its tribe, as with the familiar oak-apple, was long supposed to be a regular accessory fruit of its parent stalk. Among early students were many superstitions connected with the Bedegnar, the nature of which may readily be inferred from its other common name of "Robin's Pin-cushion."
