224
THE POPULAR SCIENCE MONTHLY
natural form, so that at the first glance you would swear the little animal was still standing there.
"Now," says Friedel, "As I read this, it can scarcely be told how saddened I was, for the hope I had previously conceived was falling into ruin." The account of Gœdart did not really seem to confirm the hypothesis about the cochineal, for there was no description of.any stage that really corresponded to the grain. Friedel was about to change his opinion in toto, when he "had another seasonable suggestion from the most excellent Dr. Lang, to whose most faithful training I owe almost everything in the course of my medical studies." For as Dr. Lang was the first to suggest to Friedel the theory about the nature of the cochineal which formed the subject of this thesis, so he now came to the rescue with facts and experiments concerning the German ladybird "depicted as in life with an elegant brush in colors, and most accurately noted from day to day," all of which, in the year just passed, Friedel was permitted to observe and confirm with his own eyes.
Sure enough, in the month of June, on the upturned leaf of the greater nettle, are seen very tiny egglets of a saffron color, adhering firmly. As may be seen in our illustration, letter g, from these, a little later, are spontaneously hatched blackish oblong little worms, below the size of a flea, but equipped with six feet on the anterior part of the little body, see letter h. These little insects are sluggish for some time after their birth, and scarcely move from their place; until, after the lapse of several days, they acquire the necessary strength, and running hither and thither, gather food, so far as we can see, from dew. [They feed on aphides, but Friedel neither observed this, nor considered the fact that mere dew was rather unsustaining!] After about three or four weeks have elapsed, they reach a size such as is indicated under letter i. At this time, they are elegantly ornamented on the sides with several yellowish spots, and their color, dark before, is changed to an ashen hue, especially along the middle of the back. Now this fleet-footed worm prepares itself for a metamorphosis, wandering more tardily at first, soon hardly at all; and then, affixing itself by its tail to a leaf, is wrinkled up as shown under letter k. By degrees the covering drops off to the rear, and it passes into the pupula or nymph, of which the anterior and posterior aspects are shown under letters l and m. The insect, even in this state, still lives, as may be learned from its movement when touched. It remains thus until the tenth and not rarely the twelfth day, when the covering is broken, and there comes forth, the skin being left motionless, a beetle, which at first is rather weak, and whitish, but changing in a few hours to yellow or red, the black spots coming into view on the elytra.
This is really an excellent account of the ladybird, excepting only the error as to its food, and from these observations Friedel felt encouraged to believe that he had put the finishing touches on his theory of the cochineal; for was not the ladybird pupa just like it? "But," says he, "if perchance this should still seem doubtful, here is a further observation to confirm it. When a friend, addicted to trade, gave me at one time a large enough heap of cochineal to examine, I
