It is extremely interesting to note that the leaf is the type of the plant in the moss as in the flowering plant; the veil being merely a convolute leaf, the lid a metamorphosed leaf, the teeth one or more whorls of minute, flat leaves. It is by no means rare to find individual mosses in which leaves appear at the top of the fruit-stalk in place of the spore-case, just as happens in the phyllode of flowering plants, when the colored parts of the flower are converted into green foliage. Mosses possess in a high degree the power of reproducing such parts of their tissue as have been injured or removed. They may be trodden under foot; they may be torn up by the plow or the harrow; they may be cropped down to the earth, when mixed with grass by graminivorous animals; they may be injured in a hundred other ways; but, in a marvelously short space of time they spring up as verdant in their appearance and as perfect in their form as though they had never been disturbed. Mosses also possess the power of resisting, perhaps to a greater extent than most plants, the injurious operation of physical agents; and this likewise is a wise provision to qualify them for the uses which they serve in the economy of nature. The influence of heat and cold upon many of them is extremely limited; some species flourishing indiscriminately on the mountains of Greenland and the plains of Africa. They have been found growing near hot springs in Cochin-China, and fringing the sides of the geysers of Iceland, where they must have vegetated in a heat equal to 186 degrees; while, on the other hand, they have been gathered in Melville Island at 35 degrees, or only just above the freezing-point. Though frozen hard under the snow-wreaths of winter for several months, their vitality is unimpaired; and though subjected to the scorching rays of the summer’s sun they continue green and unblighted. Even when thoroughly desiccated into a brown, unshapen mass that almost crumbles into dust when touched by the hand, they revive under the influence of the genial shower, become green as an emerald; every pellucid leaf serving as a tiny mirror on which to catch the stray sunbeams. Specimens dried and pressed in the herbarium for half a century, have been resuscitated on the application of moisture, and the seed procured from their capsules has readily germinated. They grow freely in the Arctic regions, where there is a long twilight of six months’ duration; and they luxuriate in the dazzling, uninterrupted light of the tropics. They are found thriving amid moist, steam-like vapors, with orchids and tillandsias, in the deep American forests; and they may be seen in tufts here and there on the dry and arid sands of the Arabian deserts. It matters not to the healthy exercise of their functions whether the surrounding air be stagnant or in motion, for we find them on the mountain top amid howling winds and driving storms, and in the calm, silent, secluded