against cold and other atmospheric influences, consists of a coating of varnish, hair or down stripped from the body of the insect, leaves drawn carefully around them, or a covering of frothy matter. The female coccus converts her whole body into a covering for her eggs, enveloping them closely on every side; the great water-beetle (Hydrophilus piceus) deposits them in a bag, and carries them at the extremity of her abdomen, like the spider commonly observed under stones, (Lycosa saccata.) In form, colour, sculpture, &c., they vary infinitely in different tribes; some of them we have already described and figured, and it will be more satisfactory to notice the peculiarities of others in connection with the particular history of the insects that produce them, than to introduce here a lengthened general account of objects so dissimilar.
The number of eggs laid by different species, is as various as their properties. At one extremity of the scale they approach the vertebrated races, at the other they surpass all other animals in the creation. Thus a pretty large fly, which may frequently be observed resting on the stems of trees, (Mesembrina meridiana) lays only two eggs, while the female white ant lays probably not fewer than forty or fifty millions in a year, extruding them, when in the act, at the rate of sixty in a minute! Of such as are intermediate between these two extremes, the numbers are, of course, very various; but it may be affirmed that insects are in general much less prolific than fishes. Among the latter, a million occurs occasionally, and half that
