The most important and significant measurement is that of the shape of the head. It is, of course, impossible to take a man at random and to say with certainty that the excessive length or breadth of his skull proves him to belong to a given race. But the average skull-measurements of a race are distinctive, and confirm, on the whole, the impressions created by general aspect, colour, language and other vaguer indications. The general result is as follows. At either end of the Himalayan range, in Baluchistan on the west, and in Assam and Burma on the east, broad heads prevail. Broad too are the heads of the mostly Mongolian races inhabiting the valleys of the southern slopes of the Himalayas, and in a belt of country running down the western coast at least as far south as Coorg. In the Panjāb, Rājputānā, and the United Provinces, tracts where the climate is dry and healthy, where great summer heat is compensated for by a bracing winter, where wheat is for the most part the staple food, long heads predominate. In Bihār, travelling eastwards, medium heads are most common. In the damp and steamy delta of Bengal, inhabited by over forty millions of rather dusky rice-eating people, there is a marked tendency towards the Mongolian brachy-cephaly of Tibeto-Burman races. It is visible among the Muhammadans and Chandāls of Eastern Bengal, people who are probably indigenous in this tract, it is more marked among the Kāyasthas, the writer-caste of Bengal, which claims a western and Aryan origin. It reaches its maximum development among the Bengali Brāhmans. South of the Vindhya mountains, where the population is chiefly Dravidian, with a comparatively small and ancient mixture of northern blood, the prevalent type is mainly long-headed or medium-headed. The coast-population has been much affected by foreign influences. On the east coast Malayan, Indo-Chinese and even Portuguese settlers have altered the local type. On the west coast, Arab, Persian, African, European, and Jewish immigrants have mingled with local races, and have changed their physiognomy, stature, and character of mind and body.