The female differs from the male in being somewhat larger in size, with the spots on the upper side of a brighter green colour, and with the marginal row of spots on the under side of the posterior wings of a pearly greyish hue, and with a tinge of this colour upon the disk of the wings. Cramer has figured the male as the female, and vice versa. Mr. Smeathman informed Mr. Drury that this insect feeds upon the orange and lime trees, about which the butterfly is always seen flying, considering it as remarkable that most of the insects which feed upon the orange or citron tribes, have some tinge of green upon them; in like manner the beautiful green snake, so common about Sierra Leone, is always to be found about these kind of trees. These circumstances led our author into a series of observations which, though upwards of half a century old, may still be read not only with pleasure, but with the hope of beneficial results. "The particular qualities, dispositions, and uses of by far the greater part of insects, as well as of plants, are at present totally unknown to us, nor are the methods by which we are to acquire that knowledge at present ascertained. "Their colours have hitherto been of no further use to us than merely to discriminate one genus or species from another; and yet it is possible that, by a combination of observations even on the colours of insects, we may form some ideas of their natures and properties. "The observation of Mr. Smeathman, if well founded, supposing it did not lead to a discovery of the nature and properties of an insect itself, might at least indicate those of the plant on which it feeds. The various species of the _Danai Candidi_, among which are included the different white butterflies of Europe, feed chiefly on such plants as are reckoned not only nourishing, but salutary to the human body, such as the various species of cabbages, coleworts, turnips, &c. Every foreign country produces butterflies of that family; some of them so very like those of Europe, that it is a fair inference they feed on plants of a similar property. This is countenanced by many corroborating circumstances. The _Papilio Iris_, and the various _Fritillary_ butterflies fly exceedingly swift; and it appears from Mr. Smeathman's observations, that foreign butterflies that bear a resemblance to them, also fly exceedingly swift. The green and golden _Scarabei_ of this country are found to delight in flowers; those of the hot climates are also found on flowers; while the black, {8}purple, and darker coloured _Scarabei_, are generally found frequenting the excrements of animals, and are, in every quarter of the globe, called Tumble dung-beetles, from their making balls of those substances, and rolling them to their holes. The locust tribes feed here chiefly on grasses and roots; so it appears they do in the torrid zone. Those of the torrid zone are found to be wholesome food. The inference is plain, that those of this