Five gentle nature essays and a postscript add up to a very lean (123-page), very likable first book by an essayist and professor (English/Bowdoin) whose work won the Pushcart Prize in 1989. A croker sack, you'll want to know, is a large burlap bag; it's also an ""emblem,"" says Burroughs, for his writing: a container that might ""reveal more than either of us would ever have expected, imagined, or hoped for."" Well, perhaps, These essays contain nothing startling, but they do catch the scents and sights of rural life. ""Snapping Turtle in June"" recalls Burroughs's boyhood turtle-watching in North Carolina, as well as recent forays with his young daughters. ""Of Moose and a Moose Hunter"" describes not only Maine's moose-hunting season, but that state's sometimes peculiar human inhabitants. ""In a Small Pond"" looks back to the trout-fishing days of Burroughs's dad (""The important thing was not to have a good time. It was to become a good fisherman""). In ""A Pastoral Occasion,"" the author unsentimentally records the destruction of his decrepit pet dog, while ""Dawn's Early Light"" sketches duck-hunting in the South. These are quiet, careful essays, chock-full of nature lore, glimmering with precision (of a snapping turtle: ""within the eye there is a strange yellowish glint, as if you were looking down into turbid water and seeing, in the depths of the water, light from a smoldering fire""). Small but stylish: more a well-tooled handbag than a croker sack.