A garden wall, and its traces of past life—Not a breath perishes—A bit of dry moss and its inhabitants—The “Wheel-bearers”—Resuscitation of Rotifers: drowned into life—Current belief that animals can be revived after complete desiccation—Experiments contradicting the belief—Spallanzani’s testimony—Value of biology as a means of culture—Classification of animals: the five great types—Criticism of Cuvier’s arrangement. Pleasant, both to eye and mind, is an old garden wall, dark with age, gray with lichens, green with mosses of beautiful hues and fairy elegance of form: a wall shutting in some sequestered home, far from “the din of murmurous cities vast:” a home where, as we fondly, foolishly think, Life must needs throb placidly, and all its tragedies and pettinesses be unknown. As we pass alongside this wall, the sight of the overhanging branches suggests an image of some charming nook; or our thoughts wander about the wall itself, calling up the years during which it has been warmed by the sun, chilled by the night airs and the dews, and dashed against by the wild winds of March: all of which have made it quite another wall from what it was when the trowel first settled its bricks. The old wall has a past, a life, a story; as Wordsworth finely says of the mountain, it is “familiar with forgotten years.” Not only are there obvious traces of age in the crumbling mortar and the battered brick, but there are traces, not obvious, except to the inner eye, left by every ray of light, every raindrop, every gust. Nothing perishes. In the wondrous metamorphosis momently going on everywhere in the universe, there is _change_, but no _loss_.