Note 19 — Chapter IV

“In general it may be said that the Philippines politically speaking, and the Philippines zoologically speaking, are not identical areas, for Balabac, Palawan, and the Calamianes Islands are strongly characterized by the presence of numerous Bornean forms which are conspicuously absent throughout the remaining islands of the archipelago. Although the Philippines are commonly held to form an eastern extension of the Indo-Malayan subregion, it should not be forgotten that at least among the birds and mammals there is a large amount of specialization in the islands to the eastward of the Balabac-Palawan-Calamianes group.... The Philippines are very poor in mammals.... They are undoubtedly well adapted to a large and diversified mammalian fauna, and the only plausible explanation of the scarcity of forms is to suppose either that they have never been connected with Borneo and the Asiatic continent or that, if at one time connected, they have since been subjected to such subsidence as to wipe out the greater part of their mammalian fauna.” (U.S. Philippine Commission’s Report, 1900, iii, p. 307.)