A third physical measurement enables us to effect a further sorting out of Indian races. What is called the "flatness" of the Mongolian face is plain to the most careless observer. This is due chiefly to the formation of the cheekbone, and its relation to the socket of the eye and the root of the nose. This can be measured and expressed in figures, with the result that the Mongoloid people of the north-east and the Himalayan region can be definitely distinguished from the broad-headed races of Baluchistan, Bombay, and Coorg. Finally, it is possible to arrive at the average stature of various Indian races and communities. The tallest races are found in the north-west, in Baluchistan, the Panjāb and Rājputānā. A progressive diminution is seen as we go down the valley of the Ganges, until we find very short folk among the Assam hill tribes. The Dravidians of the south are shorter than the Aryans of the north. The smallest Indian tribe is that of the Negritos of the Andaman Islands, whose average height is only 4 feet 10½ inches. From a careful comparison of these measurements, Sir Herbert Risley arrived at the classification of Indian humanity, which, for the moment, is the accepted division, into seven main physical types. Beginning with the north-western frontier, these are as follows:— (1) The _Turko-Iranian_ type, which comprises the Baloches, Brāhuis and Afghans of Baluchistan and the north-west Frontier Province. These are probably the result of a fusion of Turkī and Persian blood, and are all Muhammadans. The general aspect is wholly different from that of other Indian races, and no one who has ever seen an Afghan or Baloch, with his long Jewish nose and plentiful hair and beard, can ever confuse this type with any other. In temperament also these men of the border differ from other Indians. They are a fierce and warlike race, engaged in constant blood-feuds with one another.