Eggs of Lace-winged Fly.
The eggs of some insects strikingly resemble the little shells like turbans with which we are most of us familiar. A very singular variety of egg which has often caused much perplexity to naturalists is the egg of the lace-winged fly. Réaumer says, "I had observed them several years without actually knowing what they were. Others as well as myself had noticed that on the leaves and twigs of many trees were a number of minute stalks placed together, scarcely as thick as a hair, their colour was nearly white, and they were about an inch in length; there were sometimes ten or twelve placed in a bunch; the end of each stalk bore a small head of an egg-like or oblong figure. They appeared to me to be fungi, the little head precisely resembling the appearance of moulds as seen under the microscope; but they were larger in size." They were, in fact, the eggs of the fly in question. When the larva escapes from them they have much the appearance of little vases; and the same author assures us that they were once described and engraved by a naturalist as some curious minute flower growing on the leaves of the elder, for which he was unable to account. The representation of them in the cut will enable the reader to form his own opinion as to the difficulty of ascertaining whether they were flowers or the nests of an insect.
Manner of depositing the Egg.
The manner in which these eggs are thus regularly placed by the insect is interesting. Placing herself upon the leaf in the attitude represented, she fastens a thread to the leaf, draws it out in the same way as a spider does her lines, and when it has got sufficiently firm the wise insect then puts forth the egg, glueing it to the extremity of the stalk; this done, she quits it and begins to form another, repeating the same actions until the proper number is laid. Poised on the summit of these slender pillars the eggs are secure from every invader but man himself, and in time there comes from them the larva which is to become the beautiful insect, the "lace-winged fly," in all the elegance of its form.
From what has been already stated, the surface of the eggs of insects, it will be perceived, is by no means in all cases smooth and polished as in the case of birds. Far otherwise. To look at some of them by the help of a magnifying glass we should imagine that they were covered with very fine lace net, others appear as if some clever engraver had been chasing some intricate design upon their surface. The eggs of a species of butterfly are studded over with an infinite number of little knots or tubercles; and those of another are capped at the top with sculptured work disposed in the form of a circular tiling or roof to the egg. Some also closely resemble embossed buttons.
He who has thus adorned these minute objects with beauty of form and carving, has likewise bestowed upon them the most beautiful and variegated colours—colours such as no human art can imitate. But from the small size of the eggs it is difficult to appreciate this beauty in them except when they occur in a mass. The most common tints are white, yellow, and green, but the richer and rarer hues are also to be found among them. Thus, the eggs of a moth are of a beautiful blue colour, banded in the most delicate manner by three zones or rings of brown, the contrast being very pleasing. Another moth, which loves to deposit its eggs in the bark of the willow, produces them tinged with a purple more delicate than ever Tyrian lady wore as the finest produce of the dyer's art. In the deep crevices of the bark of the elm, and only, therefore, to be found by sharp scrutiny, another moth lays eggs of a lovely pink. Messrs. Kirby and Spence write, "We remember once being much surprised at seeing the water at one end of a canal in our garden as red as blood; upon examining it further we found it discoloured by an infinite number of minute red eggs." Sometimes eggs are spotted, and thus resemble the eggs of many birds; and, strange to say, sometimes they change colour in a very remarkable manner; so that, as far as colour is concerned, an observer could scarcely believe that the egg was the same he beheld, perhaps, a few days previously. The eggs of the chameleon fly, as we are told by the gentlemen last quoted, are at first pure white; then change to green, and finally turn to a deep olive-green. Others are at first mouse-coloured, then reddish, and, lastly, black. The eggs of a kind of moth we have seen first of the colour of sulphur, then becoming green, after that rose-colour, and lastly, black. In the instances of the common gnat and silk-worm, similar changes of colour take place. The eggs of the gnat are first white, then green, and finally gray; and those of the silk-worm are in the first instance of a pale yellow, and ultimately take on a violet tint.
Having thus noticed these points in connexion with the Life of an Insect, we are led to that most important of all periods, the dawn of life in the egg, or, in common terms, the period of hatching. But before proceeding to the subject, may we not pause and wonder as we behold the varied manifestations of the Creator's wisdom in the actions of the minute, and, as we often call them, insignificant creatures of whom we have spoken? Should David say, when he beheld the sun, moon, and stars, as the work of a Divine hand, "Lord, what is man, that thou considerest him, or the son of man, that thou regardest him!" And shall not we, as we contemplate the few particulars here set down of the wonders of insect-life, exclaim, with even greater astonishment, "What are these, that thou considerest them?" Let no one then say, that entomology, or any other natural science whose field of study lies chiefly among the minute portions of creation, are profitless sciences, when they can reveal to us such a display of the power, wisdom, and love of God, as is exhibited even in this small portion of the Life of an Insect.
Let us then take up one of these eggs, so minute, but containing within it the rudiments of a being which is in time to assume a form of considerable magnitude, by comparison, and to be adorned with colours richer than art can boast of, and let us examine it on the field of a tolerably powerful microscope. We need not look far for a specimen. In the dark corner of the ceiling in a neglected room, after removing the mass of dust-filled webs that have accumulated there for months, we may find without difficulty a spider's nest of eggs. A more pleasant place to search for insects' eggs is, perhaps, the garden; and if in the crevices of the bark of the trees, or attached to twigs or branches, none can be found, we can almost certainly promise success if the reader will carefully and patiently search the angles of the garden walls, particularly if he has noticed in the preceding autumn many of the beautiful webs of the garden-spider. There, in some sheltered recess, where the pattering rain-drops may be heard, but never venture in, and where few eyes would detect them, may be found little round yellow balls, of the size of a small cherry, made of the most beautiful golden-coloured silk, and attached by a slender stalk to the wall, or perhaps, to a twig. Sometimes they exhibit the more elegant and curious appearance shown in the figure on the next page, resembling an inverted wine-glass or pear.
