By the millions, primitive Indians eke out brief existences in the backlands of Latin America, cut off from the 20th centuryor the 15th century, for that matterby forbidding mountains, matted jungle and a towering cultural barrier. Their national languages, whether Spanish or Portuguese, are unknown tongues. Most of the Indians cannot even read or write their own dialects, and many tribes have no formal written language at all. Now, thanks to a private, U.S.-based outfit called the Summer Institute of Linguistics, the Indians are learning at least two of the three Rs.
The institute began training its first teams of...