Peter Matthiessen, novelist and naturalist, started on his way to South America. Five months later he came back—and wrote a book ["The Cloud Forest"]. There is nothing unusual about this. Countless gringos have visited South America, and one sometimes gets the feeling that most of them must have written books. Yet Matthiessen's trip was unusual. Somehow he managed to get to parts of the continent that have been seen by very few gringos. And, most unusual of all, he came back with a completely delightful book.

This, to my knowledge, has only happened twice before in this century; and to get this statistic we have to stretch the word gringo to include the British. But comparison with H. M. Tomlinson's "The Sea and the Jungle" and with Peter Fleming's "Brazilian Adventure" is inevitable. Among American writers on South America, Peter Matthiessen is unique.

Mr. Matthiessen, to be...