Laticiferous.-Vessels of plants, such as gutta percha, dandelion, lettuce, etc., are so called, because they contain a fluid like milk. Matrix. The substance upon which a plant grows. Membranous.-Tissue which is composed uniformly, of similarly. constructed cells is so called. Medullary rays.-Lines which radiate from the pith to the bark all round the stem of common forest trees. Nidus.-The nest or cavity in which a parasitic plant is developed. Phytozoa.-Microscopic thread-like bodies, with movements resembling those of animals, occurring in the reproductive organs of the flowerless plants. Proliferous.-Applied to plants which propagate themselves by forming new growths upon the old decaying bases. Phanerogamous.-Applied to all the flowering plants, because they are propagated by conspicuous flowers and seeds. Scalariform.-Tissue is thus called whose fibres are so broken up as to appear in the form of bars or lines, like the steps of a ladder, seen beautifully in tree-ferns. Sessile.-Seated on the vegetative basis, without stem or pedicel. Sinuses.-Deep grooves or hollows. Soredia.-Collections of mealy powder scattered over the surface of lichens, and capable of propagating them. Spore. The ultimate germinating cell of flowerless plants, without lobes, resembling a particle of fine dust. Sporule.-A minute round cell, capable of reproducing the parent plant, resembling buds in not being developed by a process of reproduction, but differing from them in being produced in special organs. Sporidia. The compound spores of lichens, containing minuter spores in their interior. Sporangia.-The hollow cases or receptacles which contain the spores. Stria.-Delicate grooved lines or markings. Tartareous.-Applied to the lime-like appearance and structure of some lichens. Thallogens.-Applied to flowerless plants whose vegetative part consists of thin cellular expansions, increasing generally in a centrifugal manner. Vascular.-Woody tissue, consisting of bundles of fine cylindrical fibres, often of great length, tapering at both ends. "URNS of beauty, forms of glory, Could e'en an empire's treasures vie, "Fringeless or fringed, and fringed again, Voices from the silent sod, INTRODUCTION. LIFE is everywhere. "Nature lives," says Lewes ; every pore is bursting with life; every death is only a new birth; every grave a cradle." "The earth-dust of the universe," says Jean Paul, ❝is inspired by the breath of the great God. The world is brimming with life; every leaf on every tree is a land of spirits." The tendency to vegetate is a ceaseless power. It has been in operation from the earliest ages of the earth, ever since living beings were capable of existing upon its surface; and so active in the past history of the globe has been this tendency, that most of the superficial rocks of the earth's crust are composed of the remains of plants. It operates with undiminished and tireless energy still. Vegetation takes place upon almost every substance; upon the bark of trees, upon naked rocks, upon the roofs of houses, upon dead and living animal substances, upon glass when not constantly kept clean, and even on iron which had been subjected to a red heat a short time before. Zoologists tell us, when speaking of animalcules, that not a drop of stagnant water, not a speck of vegetable or animal tissue, not a portion of organic matter but has its own appropriate inhabitants. A The same may be said of plants; for we can hardly point to a single portion of the earth's surface which is not tenanted by some vegetable form whose structure is wonderfully adapted to its situation and requirements. Even in the hottest thermal springs, and on the eternal snows of the arctic regions, peculiar forms of vegetation have been found. From the deepest recesses of the earth to which the air can penetrate, to the summits of the loftiest mountains; from the almost unfathomable depths of the ocean to the highest clouds; from pole to pole, the vast stratum of vegetable life extends; while it ranges from a temperature of 35° to 135° Fah., a range embracing almost every variety of conditions and circumstances. The most cursory and superficial glance will recognise in every scene a class of plants whose singular appearances, habits, and modes of growth so prominently distinguish them from the trees and flowers around, that they might seem hardly entitled to a place in the vegetable kingdom at all. On walls by the wayside, on rocks on the hills, and on trees in the woods, we see tiny green tufts and grey stains, or parti-coloured rosettes spreading themselves, easily dried by the heat of the sun, and easily revived by the rain. In almost every stream, lake, ditch, or any collection of standing or moving water, we observe a green slimy matter forming a scum on the surface, or floating in long filaments in the depths. On almost every fallen leaf and decayed branch, fleshy gelatinous bodies of different forms and sizes meet our eye. Sometimes all these different objects appear growing on the same substance. If we examine a fallen, |