A Popular History of the British Ferns Author:Thomas Moore Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: PROPAGATION, DEVELOPMENT, AND CULTURE. Naturally, Ferns are propagated by means of the spores, of which mention has been already made. These spores, which are... more » somewhat analogous to seeds, being, like them, endowed with that mystery—the vital germ, when placed under fitting conditions, become developed into young plants ; but they differ from seeds in some important particulars. All true seeds have a determinate structure. They have an embryo, provided with special organs, namely, the plumule, or germ of the ascending axis, the origin of the stem, and the radicle, or germ of the descending axis, the origin of the root. When a seed is planted, in whatever position it may chance to have been deposited in the soil, the young root or radicle strikes downwards, and the young stem or plumule grows upwards. The Fern spores have none of these determinate parts, but are, as it were, homogeneous atoms ; and when placed under circumstances which induce germination, that partwhich lies downwards produces the root, and that part which lies upwards produces the rudimentary stem. The spores are very minute cells of various shapes, mostly roundish, and often beautifully ornamented with markings on the exterior. They consist merely of a small vesicle of cellular tissue, and as they grow, this vesicle becomes divided into others, which again multiply and enlarge, until they form a minute green leaf-like patch, roundish, but irregular in outline, and unilateral, forming a primordial scale, or germ-frond, technically called the prothallus, on the under side of which certain germ-cells are produced. One of these, it appears, at length becomes the axis of development, and produces a small leaf or frond, which is usually very different in aspect as well as size from the mature fronds, and is suc...« less