A man of many talents, neurologist Sacks is not only a marvelous essayist and intrepid traveler but also a man with a keen eye for nature and an interest in traditional cultures. This book, the result of a trip to Oaxaca with (of all things) the American Fern Society displays his wide-ranging intellectual curiosity, interweaving his observations and travels with history, nature and culture of the region. A volume in the National Geographic Destinations series.  (MEX100, $14.95)