Here also we have one of the large yellow Ornithopteræ (0. magellanus), whose hind wings glow with an intense opaline lustre not found in any other species of the entire group; and an Adolias' is larger and of more brilliant metallic colouring than any other species in the archipelago. In these islands also we find the extensive and wonderful genus of weevils (Pachyrhynchus), which in their brilliant metallic colouring surpass anything found in the whole eastern hemisphere, if not in the whole world. In the Andaman Islands in the Bay of Bengal there are a considerable number of peculiar species of butterflies differing slightly from those on the continent, and generally in the direction of paler or more conspicuous colouring. Thus two species of Papilio which on the continent have the tails black, in their Andaman representatives have them either red or white-tipped.2 Another species is richly blue-banded where its allies are black; while three species of distinct genera of Nymphalidæ all differ from their allies on the continent in being of excessively pale colours as well as of somewhat larger size. 3 In Madagascar we have the very large and singularly white-spotted Papilio antenor; while species of three other genera" are very white or conspicuous as compared with their continental allies. Passing to the West-Indian Islands and Central America (which latter country has formed a group of 1 Adolias calliphorus. • Papilio rhodifer (near P. doubledayi), and Papilio charicles (near P. memnon). 3 Papilio mayo. 4 Euplæa andamanensis, Cethosia biblis, Cyrestis cocles. islands in very recent times) we have similar indications. One of the largest of the Papilios inhabits Jamaica,1 while another, the largest of its group, is found in Mexico.2 Cuba has two of the same genus whose colours are of surpassing brilliancy; while the fine genus Clothilda-confined to the Antilles and Central America is remarkable for its rich and showy colouring. Persons who are not acquainted with the important structural differences that distinguish these various genera of butterflies can hardly realize the importance and the significance of such facts as I have now detailed. It may be well, therefore, to illustrate them by supposing parallel cases to occur among the Mammalia. We might have, for example, in Africa, the gnus, the elands, and the buffaloes, all coloured and marked like zebras, stripe for stripe over the whole body exactly corresponding. So the hares, marmots, and squirrels of Europe might be all red with black feet, while the corresponding species of Central Asia were all yellow with black heads. In North America we might have raccoons, squirrels, and opossums, in particoloured livery of white and black, so as exactly to resemble the skunk of the same country; while in South America they might be black with a yellow throat-patch, so as to resemble with equal closeness the tayra of the Brazilian forests. Were such resemblances to occur in anything like the number and with the wonderful accuracy of imitation met with among the Lepidoptera, they would certainly attract universal attention. among naturalists, and would lead to the exhaustive 1 Papilio homerus. 2 P. daunus. 3 P. gundlachianus, P. villiersi. study of the influence of local causes in producing such startling results. One somewhat similar case does indeed occur among the Mammalia, two singular African animals, the Aardwolf (Proteles) and the hyæna-dog (Lycaon), both strikingly resembling hyænas in their general form as well as in their spotted markings. Belonging as they all do to the Carnivora, though to three distinct families, it seems quite an analogous case to those we have imagined; but as the Aard-wolf and the hyæna-dog are both weak animals compared with the hyena, the resemblance may be useful, and in that case would come under the head of mimicry. This seems the more probable because, as a rule, the colours of the Mammalia are protective, and are too little varied to allow of the influence of local causes producing any well-marked effects. When we come to birds, however, the case is different; for although they do not exhibit such distinct marks of the influence of locality as do butterfliesprobably because the causes which determine colour are in their case more complex-yet there are distinct indications of some effect of the kind, and we must devote some little time to their consideration. One of the most curious cases is that of the parrots of the West-Indian Islands and Central America, several of which have white heads or foreheads, occurring in two distinct genera,' while none of the more numerous parrots of South America are so coloured. In the small island of Dominica we have a very large and richly 1 Pionus albifrons and Chrysotis senilis (C. America), Chrysotis sallai (Hayti). coloured parrot (Chrysotis augusta) corresponding to the large and richly-coloured butterfly (Papilio homerus) of Jamaica. The Andaman Islands are equally remarkable, at least six of the peculiar birds differing from their continental allies in being much lighter, and sometimes with a large quantity of pure white in the plumage,' exactly corresponding to what occurs among the butterflies. In the Philippines this is not so marked a feature ; yet we have here the only known white-breasted kingcrow (Dicrurus mirabilis); the newly discovered Eurylamus steerii, wholly white beneath; three species of Diceum, all white beneath; several species of Parus, largely white-spotted; while many of the pigeons have light ashy tints. The birds generally, however, have rich dark colours, similar to those which prevail among the butterflies. In Celebes we have a swallow-shrike and a peculiar small crow allied to the jackdaw," whiter than any of their allies in the surrounding islands; but otherwise the colours of the birds call for no special remark. In Timor and Flores we have white-headed pigeons, and a long-tailed flycatcher almost entirely white.* 3 In Duke-of-York Island east of New Guinea we find that the four new species figured in the "Proceedings of the Zoological Society," for 1877, are all remarkable for the unusual quantity of white in their plumage. They consist of a flycatcher, a diceum, a wood-swallow, and 1 Kittacincla albiventris, Geocichla albigularis, Sturnia andamanensis, Hyloterpe grisola var., Ianthanas palumboides, Osmotreron chloroptera. 2 Artamus monachus, Corvus advena. 3 Ptilopus cinctus, P. albocinctus. 4 Tchitrea affinis, var. 1 a ground pigeon; all equalling if not surpassing their nearest allies in whiteness, although some of these, from the Philippines Moluccas and Celebes, are sufficiently remarkable in this respect. In the small Lord Howe's Island we have the recently extinct white rail (Notornis alba), remarkably contrasting with its allies in the larger islands of New Zealand. We cannot, however, lay any stress on isolated examples of white colour, since these occur in most of the great continents; but where we find a series of species of distinct genera all differing from their continental allies in a whiter coloration, as in the Andaman Islands, Duke-of-York Island, and the West Indies, and, among butterflies, in the smaller Moluccas, the Andamans, and Madagascar, we cannot avoid the conclusion that in these insular localities some general cause is at work. There are other cases, however, in which local influences seem to favour the production or preservation of intense crimson or a very dark coloration. Thus in the Moluccas and New Guinea alone we have bright red parrots belonging to two distinct families, and which therefore most probably have been independently produced or preserved by some common cause. Here, too, and in Australia we have black parrots and pigeons ;3 and it is a most curious and suggestive fact that in another insular subregion-that of Madagascar and the Mascarene Islands-these same colours reappear in the same two groups.* 1 Monarcha verticalis, Diceum eximium, Artamus insignis, Phloganas johanna. 2 Lorius, Eos (Trichoglossida), Eclectus (Palæornithidae). 3 Microglossus, Calyptorhynchus, Turacana. * Coracopsis, Alectrænas. |