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n or Philippine groups； to the Papuan islands； or to the Indo…Malay islands （Java； Sumatra； Borneo； and the Malay peninsula）。 Taking those families of insects and birds which are best known； the following table shows the comparison of Celebes with the other groups of islands： PAPILIONIDAE AND HAWKS； PARROTS； AND PERIDAE PIGEONS。 Percent of peculiar Percent of peculiar Species。 Species。 Indo…Malay region 。 。 。 。 56 。 。 。 。 。 。 。 。 。 。 54 Philippine group 。 。 。 。 66 。 。 。 。 。 。 。 。 。 。 73 Celebes 。 。 。 。 。 。 。 。 。 69 。 。 。 。 。 。 。 。 。 。 60 Moluccan group 。 。 。 。 。 52 。 。 。 。 。 。 。 。 。 。 62 Timor group 。 。 。 。 。 。 。 42 。 。 。 。 。 。 。 。 。 。 47 Papuan group 。 。 。 。 。 。 64 。 。 。 。 。 。 。 。 。 。 74
These large and well…known families well represent the general character of the zoology of Celebes； and they show that this island is really one of the most isolated portions of the Archipelago； although situated in its very centre。
But the insects of Celebes present us with other phenomena more curious and more difficult to explain than their striking individuality。 The butterflies of that island are in many cases characterised by a peculiarity of outline； which distinguishes them at a glance from those of any other part of the world。 It is most strongly manifested in the Papilios and the Pieridae； and consists in the forewings being either strongly curved or abruptly bent near the base； or in the extremity being elongated and often somewhat hooked。 Out of the 14 species of Papilio in Celebes； 13 exhibit this peculiarity in a greater or less degree； when compared with the most nearly allied species of the surrounding islands。 Ten species of Pieridae have the same character； and in four or five of the Nymphalidae it is also very distinctly marked。 In almost every case； the species found in Celebes are much larger than thane of the islands westward； and at least equal to those of the Moluccas； or even larger。 The difference of form is； however； the most remarkable feature； as it is altogether a new thing for a whole set of species in one country to differ in exactly the same way from the corresponding sets in all the surrounding countries； and it is so well marked； that without looking at the details of colouring； most Celebes Papilios and many Pieridae； can be at once distinguished from those of other islands by their form alone。
The outside figure of each pair here given； shows the exact size and form of the fore…wing in a butterfly of Celebes； while the inner one represents the most closely allied species from one of the adjacent islands。 Figure 1 shows the strongly curved margin of the Celebes species； Papilio gigon； compared with the much straighter margin of Papilio demolion from Singapore and Java。 Figure 2 shows the abrupt bend over the base of the wing in Papilio miletus of Celebes； compared with the slight curvature in the common Papilio sarpedon； which has almost exactly the same form from India to New Guinea and Australia。 Figure 3 shows the elongated wing of Tachyris zarinda； a native of Celebes； compared with the much shorter wing of Tachyris nero； a very closely allied species found in all the western islands。 The difference of form is in each case sufficiently obvious； but when the insects themselves are compared； it is much more striking than in these partial outlines。
From the analogy of birds； we should suppose that the pointed wing gave increased rapidity of flight； since it is a character of terns； swallows； falcons； and of the swift…flying pigeons。 A short and rounded wing； on the other hand； always accompanies a more feeble or more laborious flight； and one much less under command。 We might suppose； therefore； that the butterflies which possess this peculiar form were better able to escape pursuit。 But there seems no unusual abundance of insectivorous birds to render this necessary； and as we cannot believe that such a curious peculiarity is without meaning； it seems probable that it is the result of a former condition of things； when the island possessed a much richer fauna； the relics of which we see in the isolated birds and Mammalia now inhabiting it； and when the abundance of insectivorous creatures rendered some unusual means of escape a necessity for the large…winged and showy butterflies。 It is some confirmation of this view； that neither the very small nor the very obscurely coloured groups of butterflies have elongated wings； nor is any modification perceptible in those strong…winged groups which already possess great strength and rapidity of flight。 These were already sufficiently protected from their enemies； and did not require increased power of escaping from them。 It is not at all clear what effect the peculiar curvature of the wings has in modifying flight。
Another curious feature in the zoology of Celebes is also worthy of attention。 I allude to the absence of several groups which are found on both sides of it； in the Indo…Malay islands as well as in the Moluccas； and which thus seem to be unable； from some unknown cause； to obtain a footing in the intervening island。 In Birds we have the two families of Podargidae and Laniadae； which range over the whole Archipelago and into Australia； and which yet have no representative in Celebes。 The genera Ceyx among Kingfishers； Criniger among Thrushes； Rhipidura among Flycatchers； Calornis among Starlings； and Erythrura among Finches； are all found in the Moluccas as well as in Borneo and Javabut not a single species belonging to any one of them is found in Celebes。 Among insects； the large genus of Rose…chafers； Lomaptera； is found in every country and island between India and New Guinea； except Celebes。 This unexpected absence of many groups； from one limited district in the very centre of their area of distribution； is a phenomenon not altogether unique； but； I believe； nowhere so well marked as in this case； and it certainly adds considerably to the strange character of this remarkable island。
The anomalies and eccentricities in the natural history of Celebes which I have endeavoured to sketch in this chapter； all point to an origin in a remote antiquity。 The history of extinct animals teaches us that their distribution in time and in space are strikingly similar。 The rule is； that just as the productions of adjacent areas usually resemble each other closely； so do the productions of successive periods in the same area； and as the productions of remote areas generally differ widely； so do the productions of the same area at remote epochs。 We are therefore led irresistibly to the conclusion； that change of species； still more of generic and of family form； is a matter of time。 But time may have led to a change of species in one country； while in another the forms have been more permanent； or the change may have gone on at an equal rate but in a different manner in both。 In either case； the amount of individuality in the productions of a district will be to some extent a measure of the time that a district has been isolated from those that surround it。 Judged by this standard； Celebes must be one of the oldest parts of the