Page:Popular Science Monthly Volume 39.djvu/238

226 maroon, with some parts—the head, for example—remaining darker.

Larvæ are to be found, we might say, everywhere and in everything—on the leaves and roots and in the interior of plants, under the ground, in putrefying matter, in the tissues of living animals, in cloths, and in water. Wherever they are found, these larvæ are busy, before everything else, in alleviating the hunger of the moment.



They devour, and they gorge themselves, without taking any care to protect their existence against aggressors from without. But a more provident minority construct shelters for themselves—little movable houses which the animal carries with itself, and within which it withdraws in case of danger, like a turtle in its shell. The larva fixes itself to this refuge by means of its membranous legs, and moves without by its articulated legs. The materials necessary for the construction of the nest are gathered up in the element in which the animal lives. They are twigs, grains of sand, fragments of shells, collected in water by the Phryganeidæ, shreds taken from our cloths by the Tineidæ; earthy substances by the Chythra; and all are glued together by the secretions of the insect.

Whether in the open air or in water, or in the bottoms of underground chambers, larvæ, at a certain period of their evolution, undergo another change, and are transformed into nymphæ. Among the insects of incomplete metamorphosis, the nympha is but little different from the larva, and molts and is fed in the