Some groups of butterflies are remarkable for the imperfect development of the first pair of legs, so that they are generally described as having four legs instead of six.
The eggs of butterflies are deposited on the plants, the leaves of which are to supply the food of the caterpillars. In cold and temperate climates, the eggs deposited in autumn arenot hatched till the following spring; but it is believed that many species produce several broods in a year, as the eggs in summer may be hatched in a few days. The caterpillars of each species are generally confined to some particular kind of plant, the leaves of which they devour; their ravages are well known, but the excessive increase of their numbers is in part restrained by many enemies, and by none more than by the ichneumons (q.v.) and other insects, which deposit their eggs in them, and the larvae of which feed on them. An account of B. transformations will be given under INSECT TRANSFORMATIONS. f Butterflies vary in size from less than an inch to almost a foot across the expanded wings. The largest species are tropical. Some of the species are very widely distrib uted; Cynthia cardui, of which the caterpillar feeds on the leaves of thistles, is found not only throughout Europe, but in Egypt, Barbary, Senegal, Cape Colony, Madagas car, China, Java, Australia, Brazil, and North America, being, in fact, one of the most widely distributed of all insects. The geographical limits of other species appear to be very restricted. The diversity of coloring is almost endless, but a prevalence of cer tain hues, or of certain modes of the disposal of them, is observable throughout large groups. The caterpillars of many species are variously furnished with spines, those of
others—none of them British—have long fleshy prominences, horny at the tip, probably intended as means of defense. The hinder wings of many butterflies are curiously prolonged into tail-like appendages, one or more on each wing, which vary in form, being sometimes long and linear, sometimes broad, and widening towards the extremity. These are, however, little seen in British species.
Butterflies are chiefly known to us as objects of admiration and of pleasing contem plation, enhancing the charms of the most delightful weather, and always associated with the most lovely scenes, or—it must be added—as a cause at annoyance and vexa tion by the ravages of their caterpillar young in our fields and gardens. There is, how ever, one small species (euplea humata) which affords a supply of food to some of the wretched aborigines of Australia. Butterflies of this species congregate in such vast numbers on the masses of granite in the mountains, that they are collected by simply making smothered fires under the rocks, in the smoke of which they are suffo cated. Bushels of them are thus procured, and they are baked by placing them on the heated ground, the down and wings removed, and the bodies made into cakes which resemble lumps of fat. The months of Nov., Dec., and Jan. are quite a season of fes tivity from the abundance of this food.
Brief notices of a few of the principal kinds of B. will be found in other parts of this work. See CABBAGE BUTTERFLY, CAMBERWELL BEAUTY, PURPLE EMPEROR, etc.