INTRODUCTION.
But O! what terms expressive may relate
The change, the splendour of their new-formed state!
Their texture, nor composed of filmy skin,
Of cumbrous flesh without, or bone within,
But something than corporeal more refined,
And agile as their blithe informing mind.
In every eye ten thousand brilliants blaze,
And living pearls the vast horizon gaze;
Gemmed o’er their heads the mines of India gleam,
And heaven’s own wardrobe has arrayed their frame:
Each spangled back bright sprinkled specks adorn,
Each plume imbibes the rosy tinctured morn,
Spread on each wing the florid seasons glow,
Shaded and verged with the celestial bow.
Where colours blend an ever varying dye,
And wanton in their gay exchanges vie.
Brooke.
Having already discussed the general history of butterflies at considerable length, in a volume devoted to the illustration of the kinds found in Britain, it is not our intention to resume the subject in this place, further than to make a few remarks on certain peculiarities presented by many foreign species, a selection from which forms the subject of the present volume.
The remarkable superiority in size and beauty of most tropical productions over those of temperate regions, is scarcely more strikingly exemplified in any department of nature than in this. The most richly ornamented of our native species, and we possess many of great beauty, appear insignificant when contrasted with those of Brazil and Eastern Asia. Various as are the modifications of form which they present in this country, we find nothing to prepare us for the peculiar outline and aspect which many kinds assume in the warmer regions of the earth. Here we seldom find any having the hinder wings prolonged into a tail, but among foreign species this is a common appendage, sometimes long and linear, at other times broad and spatulate; and occasionally there are not fewer than three or four on each of the hinder wings. Along with this variety of outline, they exhibit almost every possible shade of colour, from the most brilliant to the most obscure, combined and blended in the most elegant and harmonious designs, rendering this tribe of creatures one of the most ornamental to be found in nature.
Although such endless diversity of colouring is observable in this class as a whole, it is, at the same time, worthy of remark, that most of the principal groups are characterized by the prevalence of particular hues, as well as considerable uniformity in their mode of distribution; that is to say, certain modifications of structure are generally accompanied with a certain pictorial design. Thus, the greater proportion of the genus Pieris are white; Colias and Callidryas various shades of yellow, from the palest sulphur-yellow to deep reddish-ochre. Argynnis is almost invariably fulvous or reddish brown, variegated with numerous undulating black lines or spots; the under side more or less ornamented with silvery streaks and spots. In the species of the European genus Thais, the wings are spotted or chequered with black and red. The prevailing colour in the genus Argus is azure-blue. Danais, Idæa, and Euplœa, have this character in common, that the breast and head are always punctured with white. In Cethosia, hieroglyphical markings cover the under side of the wings in such a manner as is observable in no other genus.
Many of the caterpillars of exotic butterflies offer peculiarities in their forms and appendages, of which we find no prototype in the kinds occurring in Britain. In the place of spines, some have the body thickly covered with long fleshy prominences, of a corneous consistency at the tip, and probably serving as a means of defence. In others, spines of singular conformation and formidable size are thickly stuck over the whole surface, making it resemble a miniature forest. A few are provided with a long anal horn, resembling that which is so conspicuous in the caterpillars of the Sphinges. If Madam Merian’s delineation of the larva of Urania Leilus be correct (which there is now reason to believe is the case), it bears many slender spines, as long as the whole body, and as stiff as iron wire. Another species (that of Papilio Protesilaus), is likewise clothed with plumose spines, two of which at the hinder extremity are much longer than the rest, and terminate in an appendage like a star. Equally remarkable with any of these is the caterpillar of one of the Nymphalidæ (Adoleas Aconthea), which has a series of long filiform bodies projecting from each side, thickly clothed laterally with hairs of considerable length diminishing gradually to the extremity, which is armed with a few minute spines.
As might be expected, great diversity likewise prevails in the appearance of the chrysalides; but to these it will be more convenient hereafter to refer, in the preliminary notices to the respective genera. One of the most remarkable, however, may be mentioned, that of Morpho Menelaus, which has the nasal prominence of the prothorax produced into a long curved horn, which extends to the middle of the abdomen. In another species of the same group, the head is obtuse, projects considerably, and is curved upwards at the extremity, exactly like the beak of an ancient galley.
Our acquaintance with the geographical distribution of the diurnal lepidoptera was long very imperfect, and it may yet be said to be very far from complete. The older naturalists seem to have been but little alive to the importance of the subject, and even if it had been otherwise, the means they possessed for illustrating it were comparatively limited. Those who had opportunities of collecting specimens in foreign countries, valued them merely as specimens, and, in general, kept no record of their localities, or natural history properly so called. Collections from China and the East Indies were indiscriminately mixed, in their way homewards, with others from the Cape of Good Hope; and American species were in like manner mingled with such as are proper to the West Indian islands. Hence it followed, that Fabricius and others were so often led into error when they indicated the native country of the kinds they described: but, indeed, the author just named did not very frequently attempt this, but merely says, “From the Indies”—an expression which means nothing more explicit, in his acceptation of it, than that the species in question is exotic. Linnæus, also, when he uses the same word, means indiscriminately either the East or West Indies. The indications of localities in modern works are in general copious and accurate, but they have not hitherto been made the basis of any general and satisfactory view of the distribution of the species.
As might be expected in the case of animals endowed with considerable power of flight, certain kinds of diurnal lepidoptera have a much more extensive range than most other insects—than the coleoptera for example. It is now ascertained that Cynthia cardui, a species well known throughout Europe, (without confounding it, as may sometimes have been done, with the kindred species C. Hunteri), occurs in Senegal, Egypt, Barbary, Cape of Good Hope, in the islands of Bourbon and Madagascar, in Bengal, China, Java, New Holland, Brazil, and North America; so that it may be called a complete cosmopolite. Of the four quarters of the globe, Europe is poorest in these insects; and next to it is Africa. Asia, including the great islands of the Indian Archipelago and America, are both exceedingly rich. Of the former, the islands seem to be much more prolific than the continent; they are the exclusive haunts of the gigantic Ornithoptera, several of the largest and most richly coloured of the Pierides, as well as several of the most remarkable species of the genus Morpho. South America produces a greater number than any other country; and Brazil, always preeminent for its exuberance both in animal and vegetable life, may be said to be the richest portion of the new continent. It has been estimated by an individual who has enjoyed the advantage of personally examining the country, that Brazil alone affords between 600 and 700 species of diurnal lepidoptera, a calculation which seems in no degree overcharged. Among these are many genera peculiar to America, such as Heliconia, Castnia, Erycina, &c. In almost every one of its physical properties, Africa affords a complete contrast to the country just named; and however favourable its arid soil, and far-extending deserts of parched and drifting sand, may be to the existence of certain peculiar races of coleoptera, it is by no means generally adapted to the support of creatures which derive their entire sustenance from vegetable juices. The sea-coast, and umbrageous banks of the larger rivers, however, are pretty abundantly supplied, and afford many species peculiar to the country. This is the metropolitan station of the genus Acrea, and it is likewise inhabited by several peculiar groups of the genera Papilio, Pieris, &c. The neighbouring island of Madagascar is much richer than the continent, and exemplifies what has been observed in relation to many other islands, that their zoological productions by no means correspond to those of the nearest portion of the main land. Little relation exists between the diurnal lepidoptera of Madagascar and the Cape of Good Hope, but a very close one can be traced between the former and those inhabiting distant parts of the continent, such as Senegal and Sierra Leone. Mauritius and Bourbon likewise differ considerably in their lepidopterous productions from Madagascar. In the latter, magnificent Papilios, Acrææ, Euplœæ, Danaides, Uraniæ, Cyrestes, and Xanthidia, embellish by their elegant forms and splendid colours, the marshy and pestilential forests of that extensive island, and rival in beauty that majestic and teeming vegetation which has always excited the admiration of botanists[22]. New Holland is not without its peculiar species, although this department of its zoology is not characterised by such marked singularities as are observed among its higher animals and vegetable productions.