l the Malay Islands, and also perhaps introduced;
the curious Malayan tarsier (_Tarsius spectrum_) said to be only found in a
small island off the coast;--and besides these, three remarkable animals,
all of large size and all quite unlike anything found in the Malay Islands
or even in Asia. These are a black and almost tailless baboon-like ape
(_Cynopithecus nigrescens_); an antelopean buffalo (_Anoa depressicornis_),
and the strange babirusa (_Babirusa alfurus_).

None of these three animals last mentioned has any close allies elsewhere,
and their presence in Celebes may be considered the crucial fact which must
give us the clue to the past history of the island. Let us then see what
they teach us. The ape is apparently somewhat intermediate between the
great baboons of Africa and the short-tailed macaques of Asia, but its
cranium shows a nearer approach to the former group, in its flat projecting
muzzle, large superciliary crests, and maxillary ridges. The anoa, though
anatomically allied to the buffaloes, externally more resembles the bovine
antelopes of Africa; while the babirusa is altogether unlike any other
living member of the swine family, the canines of the upper jaws growing
directly upwards like horns, forming a spiral curve over the eyes, instead
of downwards, as in all other mammalia. An approach to this peculiarity is
made by the African wart-hogs, in which the upper tusk grows out laterally
and then curves up; but these animals are not otherwise closely allied to
the babirusa. {457}

_Probable Derivation of the Mammals of Celebes._--It is clear that we have
here a group of extremely peculiar, and, in all probability, very ancient
forms, which have been preserved to us by isolation in Celebes, just as the
monotremes and marsupials have been preserved in Australia, and so many of
the lemurs and Insectivora in Madagascar. And this compels us to look upon
the existing island as a fragment of some ancient land, once perhaps
forming part of the great northern continent, but separated from it far
earlier than Borneo, Sumatra, and Java. The exceeding scantiness of the
mammalian fauna, however, remains to be accounted for. We have seen that
Formosa, a much smaller island, contains more than twice as many species;
and we may be sure that at the time when such animals as apes and buffaloes
existed, the Asiatic continent swarmed with varied forms of mammals to
quite as great an extent as Borneo does now. If the porti