On the north edge of Provincetown the migrant dunes skirt the woods and thickets on their borders like icebergs, clean-rounded, immense shoulders of satiny sand slipping by trees: shad, bayberry, beach plum, red maple, oak, or pine. Because of the stable nature of sand, except when it is blown, they stay where they are, great suspended masses, their progress only measured at intervals, leaving evidence of trees that are buried, or about to be buried, behind them. I am indebted to Dr. Loren C. Petry for pointing out to me that some trees are able to grow in the same way as beach grass, while they are being covered with sand. Pines will die when they are only partially buried, but this is not true, for example, of cottonwoods whose branches send down roots soon after they are buried, and so maintain their water and mineral supply. He has seen fifty-foot specimens of this tree--along the southeast side of Lake Michigan--of which some forty feet were buried, with the remaining ten feet growing vigorously. The trees in the wooded areas bordering the dunes, particularly the pines, look as if they were covered with a soft whitish powder. It is caused by the very fine sand grains dusted over their leaves and needles by the wind, and during the winter this can be seen for miles down the Cape, well south of High Head. Almost all the trees here have a temporary existence, holding on as well as they can, fighting for light, food, and moisture. Even if there used to be more woodland than there is now--and the evidence is good--there is nothing about this narrow area, stretching into the sea, made by the sea in collaboration with the wind, that looks settled. The word stabilized can be applied to a dune and in a sense to anything that remains rooted, anchored, or in place for a certain length of time, but in this case the word balance might be better. Motion, either latent or in view, is in equilibrium throughout this rare place, half desert, occasionally wooded, full of gardenlike patches of low growth standing out in their variety of color and shade, seeming to move like the clouds. There are shadows everywhere, made by low twigs, needles, or grasses, the slightest thing lying across the sand, in sketchy rhythmic patterns tossed by the wind, while the greater shadows made by the high dune outlines are shifting steadily with the time of day.