The geographical distribution of animals, with a study of the relations ...

—;428 ZOOLOGICAL GEOGRAPHY. [past hi.Australian form is represented in Celebes by two peculiarspecies.Leaving out the Indo-Malay species, which may probably havebeen introduced by man, and are at all events comparativelyrecent immigrants, and the wild pig, a genus which ranges overthe whole archipelago and which has therefore little significance,we find two genera which have come from the Australian side,— discus and Mus ; and four from the Oriental side, Cynopithecus,Anoa, Bahirusa, and Sciurus. But Sciurus alone correspondsto discus, as a genus still inhabiting the adjacent islandsthe other three being not only peculiar to Celebes, but incapableof being affiliated to any specially Oriental group. We seem, then,to have indications of two distinct periods ; one very ancient,when the ancestors of the three peculiar genera roamed over someunknown continent of which Celebes formed, perhaps, an outlyingportion ;—another more recent, when from one side there enteredSciurus, and from the other discus. But we must rememberthat the Moluccas to the east, possess scarcely any indigenousmammals except Cuscus ; whereas Borneo and Java on the west,have nearly 50 distinct genera. It is evident then, that thefacilities for immigration must have been much less with theOriental than with the Australian region,and we may be prettycertain that at this later period there was no land connectionwith the Indo-Malay islands, or some other animals than squirrelswould certainly have entered. Let us now see what light isthrown upon the subject by the birds.Birds.—The total number of birds known to inhabitCelebesis 205, belonging to about 150 genera. We may leave out ofconsideration the wading and aquatic birds, most of which arewide-ranging species.of land-birds,There remain 123 genera and 152 speciesof which 9 genera and 66 species are absolutelyconfined to the island, while 20 more are found also in the Sulaor Sanguir Islands, so that we may take 86 to be the number ofpeculiar Celebes species. Lord Walden, from whose excellentpaper on the birds of Celebes (Trans. Zool. Soc. vol. viii. p. 23)most of these figures are obtained, estimates, that of the specieswhich are not peculiar to Celebes, 55 are of Oriental and 22 of