Page:Popular Science Monthly Volume 48.djvu/268

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OHANNES SWAMMERDAM, a Dutch naturalist, who was the first to examine insects with a microscope, and whose investigations were published in 1757, gave some curious details concerning the eggs of insects. "Some are oblong," he said, "others ovoid or round. There are also angular, pyramidal, striated, and granular eggs, etc. They are no less various as to colors, and we find them white, yellow, red, blue, green, and pied with different colors so singularly combined that it is almost impossible to describe them exactly. In consistence, some are soft, others hard; some membranous, others covered with a coat like parchment or with a real eggshell; some are covered with a kind of froth, others with hairs."

Swammerdam described with many details the eggs of the Nepa cendrea, a little fresh-water hemipter, which he called the water scorpion (Fig. 10). They are yellow and nearly of the same shape as the seed of the blessed thistle, slightly elongated, and rounded at the lower end. On the upper part they are provided with seven or eight slender branches, or hard threads, of which the point is red and the middle whitish. These appendages or threads, arranged in a circle around the circumference of the summit of each egg, form a kind of open egg cup, which receives the end of the next egg in its cavity. Thus these appendages of the first egg hold the lower end of the second, and so on.

The eggs of the Lepidoptera, have considerable resemblance to the seeds of plants (Figs. 1, 3, 3, 4). "Those of the larger and smaller cabbage butterflies have the shape of a pyramid, of a height three or four times the diameter of the base, and the base is stuck to a leaf. The eggs are usually formed by eight rounded ribs, separated by flutings running from the summit to the larger end. On each of these sides may be seen an infinite number of flutings parallel to the base. The eggs of the great tortoise butterfly are nearly spherical, and are smaller in diameter at the base, or the part by which they are attached to the plant, than at the summit, whence eight equally distant crests descend along the body of the egg, forming ribs which diminish imperceptibly in height and disappear before reaching the end."

These eggs resemble those of a night moth which attaches its