Similar in distribution and in mode of life are the aborigines of the Philippines, the dwarf Negritos, who are still found inhabiting the forests in various localities. They are dispersed through eight provinces of Luzon and in several other islands, generally in the interior, whither they have been driven by the invading Malays.[275] [See map page 147.] But the Negritos crop out again in the mountain interior of Formosa and Borneo, in the eastern peninsula of Celebes, and in various islands of the Malay Archipelago as far east as Ceram and Flores, amid a prevailing Malay stock. Toward the west they come to the surface in the central highland of Malacca, in the Nicobar and Andaman Islands, and in several mountain and jungle districts of India. Here again is the typical geographic distribution of a moribund aboriginal race, whose shrivelled patches merely dot the surface of their once wide territory.[276] The aboriginal Kolarian tribes of India are found under the names of Bhils, Kols and Santals scattered about in the fastnesses of the Central Indian jungles, the Vindhyan Range, and in the Rajputana Desert, within the area covered by Indo-Aryan occupation.[277] [See map page 103.] [Sidenote: Discontinuous distribution.] Such broad, intermittent dispersal is the anthropological prototype of the "discontinuous distribution" of biologists. By this they mean that certain types of plants and animals occur in widely separated regions, without the presence of any living representatives in the intermediate area. But they point to the rock records to show that the type once occupied the whole territory, till extensive elimination occurred, owing to changes in climatic or geologic conditions or to sharpened competition in the struggle for existence, with the result that the type survived only in detached localities offering a favorable environment.[278] In animal and plant life, the ice invasion of the Glacial Age explains most of these islands of survival; in human life, the invasion of stronger peoples. The Finnish race, which in the ninth century covered nearly a third of European Russia, has been shattered by the blows of Slav expansion into numerous fragments which lie scattered about within the old ethnic boundary from the Arctic Ocean to the Don-Volga watershed.[279] The encroachments of the whites upon the red men of America early resulted in their geographical dispersion. The map showing the distribution of population in 1830 reveals large detached areas of Indian occupancy embedded in the prevailing white territory.[280] The rapid compression of the tribal lands and the introduction of the reservation system resulted in the present arrangement of yet smaller and more widely scattered groups. Such islands of survival tend constantly to contract and diminish in number with the growing progress, density, and land hunger of the surrounding race. The Kaffir islands and the Hottentot "locations" in South Africa,