Considered to be the very first natives of India, the Adivasi tribes are thought to have been driven into jungles, deserts and mountains thousands of years ago by Caucasian invaders. The 250 tribes, with a total population of roughly 60 million, were perennially discriminated against by the Hindus, though Prime Minister Nehru began a policy of safeguarding their development. One tribe, the Bihli formerly hunters and fishermen, must now farm relatively unfertile land granted to them by the government.