20 



BRITISH MOSSES. 



found on decayed animal matter, may countenance the belief that through the root 

 food is supplied to the moss as to other plants. 



Besides a root, a moss has stem, leaves, and fruit. The stem may be with or 

 without branches. The leaves next come under consideration. The cells of which 

 they are composed are of various forms, the most remarkable and beautiful being 

 found in the Sphagnum group, the Mniums, and the Hooherid lucens. One general 

 form in each genus is maintained, but they are very irregular in size and arrange- 

 ment. (See Illustrations) . The leaves themselves differ much in shape ; very 

 rarely they are divided, but their edges are often serrated. They may be lance- 

 shaped, scymitar-shaped, sickle-shaped, awl-shaped, egg-shaped, sometimes be- 

 tween lance and egg shaped, set flat to the stem, which then looks like braidwork, 

 or set out from it all round, as are the hairs of a fox's tail ; very often they twist 

 every way when dry, and again when dry they may be waved cross- wise, or furrowed 

 length-wise. In size they vary between minute close-pressed scales, and broad, 

 gauze-like, waved leaves, nearly half-an-inch in length ; they have no sap-vessels, 

 but often possess one or two nerves, which nerves reach half-way up the leaf, or some- 

 times less ; and when the nerve is single it frequently runs out into a point beyond 

 the leaf. The leaves of mosses may also have thickened margins ; but in both form 

 and structure are many more varieties than these. The principal ones only are 

 here named, and the others will be learnt when each moss is examined in detail. 



Those who have observed the formation of an ordinary seed will know that it 

 consists of one or more lobes, at the base of which is the bud, designed to develope 

 afterwards into the future plant; and that when the seed first germinates, the 

 enlarged lobes are the earliest part to appear above ground as leaves, differing 

 from the true leaves, which appear on the developed germ. These seed or nurse 

 leaves are called Cotyledons ; but the seeds of A-cotyledons (without seed-leaves) 

 are simply a collection of cells ; and these do not sprout or spring from one point, 

 but gradually expand into a green film. Cell developes from cell ; next stems 

 and little leaves appear, so delicate that a touch will crush them ; and this process 

 continues month after month, so slowly and quietly that it will be revealed only 

 by very close observation, until we see that the green films have changed into tiny 

 plants, each bearing a seed-vessel of its own. Many mosses are of rapid growth, 

 but others, in proportion to their size, are among the slowest of vegetable growers, 

 and they are both annual and perennial in duration. 



