This ""ultimate safari"" to the ultimate wilderness, the 22,000-square-mile Selous Game Reserve in southeastern Tanzania, was conceived and sponsored by a young British MP who contracted with writer Matthiessen and photographer van Lawick to do the book that would help underwrite the expedition. The safari's leader was the Selous' 49-year-old former warden Brian Nicholson, a crusty Colonial now distressed by deterioration of the system he built and disturbed by reports of poaching and depleted elephant herds. Others in the party were Matthiessen's friend Maria and Nicholson's wife and grown children. But it was Matthiessen and Nicholson ""alone"" (with African porters, cook, and gun bearer) who took the long foot safari to a spot where no white man but Nicholson had been--and it is Nicholson as Matthiessen comes to know him who becomes the focus of Matthiessen's account. Nicholson, who affects a gruff manner and claims to value snakes over people, speaks of the thousands of animals he has killed but violates ""the heart of the Selous"" with sad reluctance, shooting a buffalo to appease the weary load-bearers' demand for meat. He delights in shocking Matthiessen's more liberal sensibilities with his old-line attitudes toward the Africans, but eventually drops his mask, concedes respect for a number of his former employees (some along with him now), and proves as Matthiessen has suspected ""a good deal more complex than the anachronism he seemed to wish to represent."" Matthiessen observes various stages of racial accommodation among both the whites in the party and the Africans, who seem genuinely fond of ""Bwana Niki""--though one staff member's mocking performance when his fellows stage a good-will song and dance for their employees is received with uneasy giggles on both sides. There is no disagreement, though, on the importance of preserving this last stronghold of wildlife. All are awed by the lions and leopards who roar through the night; the ""magnificent"" kudu who pass ""like monuments""; the elephants, surprised at uncomfortably close range, who send porters scurrying and evoke Nicholson's cautionary recollections; and the rhino, with her calf, who seems about to charge but doesn't. ""That was worth the whole safari,"" says Matthiessen when the still moment has passed. Matthiessen, who's adept at making the most of the material on hand, gets to know the former who knows how to use the available material to the fullest, makes the region's changing relationships part of the story. Intrinsically this is not on a par with some of his earlier books, but--bolstered by the pictures--it will be of certain interest nonetheless.