Page:Encyclopædia Britannica, Ninth Edition, v. 4.djvu/659

Rh BUTTERFLIES 595 fardui), a common British species, being found in every quarter of the globe ; and our finest butterfly, the Swallow Tail (Papilio mackaon), occurring throughout Europe, Asia as far as the Himalayas, and South Africa. Other species are extremely local, as the Scotch Argus (Lyccena artaxerxes), confined to a few Scottish hillsides. Keferstein estimates the total number of Lepidoptera at G6,000 species GOOD butterflies and 60,000 moths. That such estimates, how ever, are not to be relied on is sufficiently proved by the fact that Bates gives the number of species as above 200,000. The geographical distribution of certain groups of Lepi- doptera has been well wrought out by Mr Wallace and other naturalists who have studied them in their native homes ; but the division of this great order into geographical zones has still to be satisfactorily accomplished. Koch has recently proposed to place them in five such groups (1) the European or Western fauna, including Northern Asia, the North of Africa (a region exceedingly poor in Lepi- Joptera, owing probably to the want of great forests, and to the marshy nature of vast tracts of land), and the northern parts of North America; (2) the African fauna, allied to the preceding ; (3) the South Asiatic or Indian ; (4) the Australian and Polynesian, allied to the Indian ; and (5) the American fauna, distinguished by its exceeding richness. BUTTERFLIES. Linnasus included all butterflies under the single genus Papilio, but later writers have divided them into several well-defined families, and into numerous genera. The largest and most magnificent species belong to the Ornithoptera or &quot; Bird-winged Butterflies,&quot; a genus of Papilionidce, whose wings, measuring fully 7 inches across, are of a velvety black and brilliant green colour, the latter in such species as Ornithoptera crcesus being replaced by fiery orange, while the body is golden, and the breast crimson. They are distributed over the islands of the Malay Archipelago, reaching, according to Mr Wallace, their maxi mum of size and beauty in the Moluccas. ThePapihos are a closely allied group, smaller in size but equally brilliant in the colour and form of their wings. They are exceedingly numerous and are widely distributed over both hemispheres. One species only is found in Britain, the handsome Swallow Tail (Papilio machaon) (Plate XXVII. figs. 1, 2), formerly abundant in many parts of England, but now confined to the fen districts of Cambridgeshire, Norfolk, and Huntingdon. When alarmed the larvae of this and of other species of Papilios protrude from the upper part of the neck a soft forked horn that usually diffuses a penetrating and unplea sant odour. One of the most elegant of exotic species is the Malayan Papilio memnon, with black and blue wings, 6 inches in expanse, and with the edges of the hind pair gracefully scalloped. This butterfly, though common enough in collections, has recently gained additional in terest from the fact, discovered by Mr Wallace, of the remarkable variety in the form of the females, a variety which has led to their being described under several specific names. In one group the females resemble the males in shape, though differing greatly as many female butterflies do in colour. In another group they differ both in colour and in the form of the hind-wings. These, Mr Wallace says, are &quot; lengthened out into large spoon- shaped tails, no rudiment of which is ever to be perceived in the males or in the ordinary form of the females.&quot; He also found that in shape and colouring those tailed females when on the wing, closely resembled another butterfly belonging to a different section of the same genus, Papilio coon, which he considers is thus mimicked by the erratic females of Papilio memnon. Strange to say both forms of female are produced from the eggs of either form. The genus Parnassius, which seems peculiar to the Alpine or Bubulpine countries of Europe and the North of Asia, belongs also to the Papilionidce. One species, Parnassius apollo (Plate XXVII., fig. 3), has semi-transparent wings, spotted with black and vermilion, and is common in most of the mountain ranges of Europe, where it forms a very striking object. The Brimstones (Gonepteryx), the Clouded Yellows (Colias, Plate XXVII. fig. 4), and the White Butter flies (Pieris, Plate XXVII. fig. 6), many of which are abun dant in Britain, and the larvae of which in most cases make great havoc among garden vegetables, belong to the family Pieridce. That the caterpillars of this group are not fatal to the very existence of certain of our most useful vegetables is due solely to the ravages of the ichneumon flies, the larvae of which are parasitic upon these cater pillars, to such an extent that in every hundred larvae of the common Cabbage Butterfly, there are probably not more than two or three entirely free from the ichneumon fly (Microgaster glomerata], and few caterpillars so attacked ever reach maturity. The species belonging to the family Nymphalidce have only four legs fitted for walking, the anterior pair being rudimentary. They include the ma jority of the showy butterflies of temperate regions, as the Peacock Butterfly (Vanessa io, Plate XXVII. fig. 9), con spicuous from the &quot;eyes &quot;on the upper surface of its wings. The brilliant colouring of the upper surface is in marked contrast to the sombre hues of the under, which give it when resting on the branch of a tree the appearance of a dried leaf, and so is to a considerable degree protective. The Fritillaries (Argynnis, Plate XXVIII. fig. 2) have the under surfaces of the wings ornamented with shining silvery disks, and, except a few tropical species, are the only butterflies which have the under surface more gaily coloured than the upper. The Purple Emperor (Apatura iris) is one of the largest and most striking of British species. It is a powerful flyer, frequenting the tops of the highest trees, and is thus difficult of capture unless when brought near the ground by the attraction of some putrid carcase. To the same family belongs Nymphalisjasius (Plate XXVIII. figs. 7 and 9), one of the most beautiful of European species. The Heticonidce (Plate XXVII. fig. 7) are a family of South American butterflies, so numerous both in species and in individuals, and of such showy colours on both surfaces of the wings, as to form, says Bates, &quot; a feature in the physiognomy of the forest compensating for the absence of flowers.&quot; Their wings are long and narrow, they fly lazily, and might thus be supposed to be specially liable to the attacks of insectivorous animals. As already stated, such is not the case, these insects being apparently protected by the nauseous character of their juices. It is this group which is chiefly mimicked in South America, finding imitators in several species of Leptalis, a genus of butterflies belonging to the family Pieridce, also in several species of Erycinidce, and in no fewer than three genera of day-flying moths -all belonging to edible groups. The family Morphidce (Plate XXVIII. fig. 8) contains the largest and most splendid of the South American butterflies. Their wings, often 7 inches in expanse, are generally of a brilliant metallic blue, which, as the insect flies, flashes in the sunlight so as to be visible, it is said, a quarter of a mile off. They are found most abundantly in forest glades, through which they sail, only flapping their wings at considerable intervals at a great height, &quot; seldom,&quot; says Bates, &quot; descending nearer the ground than 20 feet.&quot; The Satyridce (Plate XXIX. fig. 6) are found in every quarter of the globe, and seem equally at home on open plains, in forests, and on the slopes of mountains. Their larvas feed chiefly on grass, and have the almost unique habit of remaining concealed by day and of coining forth at night to feed. The Marbled White (Arge galathea) is the species oftenest met with in Britain. The Hctairce of Brazil, the wings of which are partly transparent, belong to this