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 Java--but 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
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