How quickly a mould attacks and creeps or spreads through a basin of berries every one knows. The mould is as much a plant as the bush that produced the berries; it comes from a small spore, which takes the place of a bud or sprout or seed. The decay of a tree begins where a limb or root has been injured, and whether the timber is living or dead, this decay results from the growth of some one or more low forms of plant life which enter the timber in certain places and slowly or quickly penetrate and affect other portions more or less remote. CHAPTER II. PLANTS SPREAD BY MEANS OF ROOTS. 3. Fairy rings.--Several low forms of plant life, such as _Marasmius oreades_, _Spathularia flavida_, and some of the puffballs, start in isolated spots in the grass of a lawn or pasture, and spread each year from a few inches to a foot or more in every direction, usually in the form of a circle; at the end of fifteen years some of these circles acquire a diameter of fifteen to twenty feet or more. These are known as fairy rings. Before science dispelled the illusion they were believed to have been the work of witches, elves, or evil spirits, from which arose the name. Several kinds of lichens and mosses and the like, growing on the barks of trees, fence boards, and low ground, spread slowly in the manner of fairy rings. However, the spreading is not always a slow, creeping process, for sometimes these low plants spread over an incredible distance in a short space of time. In some instances they appear suddenly almost anywhere, and at any season of the year. They are all minute and exist in countless numbers, and their devices for securing wide dispersion are so various as to entitle them to first rank in this respect. Some send off spores with a sharp puff, as if shot from a little gun. Some of these spores float on water, and some are sticky and thus gain free rides. It is not at all improbable that some are carried by the winds across oceans and continents. It is well known that many of the lower species of plants are more widely distributed over the earth than most of the higher plants. Every cloud from a ripe puffball consists of thousands of spores started on the wings of the wind for an unknown journey. Their habits are not past finding out, but to examine them a person needs a good microscope. Most of them have no special common name, and with one or two exceptions further mention of the mode of distribution of this fascinating portion of plant life cannot here be made.