INTRODUCTION. 



21 



In the botanical system of Linnaeus mosses were placed among the Crypto- 

 gamic plants. It is true that the various parts of their fruit are so small as only 

 to be fully examined by the help of a microscope, but the flower and fruit as a 

 whole may on most species be easily seen. Their true nature has only been 

 recently understood ; and it is now ascertained that mosses have real flowers, 

 differing indeed from the flowers of other tribes of plants, but having parts which 

 answer to those of larger and more showy blossoms. For a detailed account of 

 these the reader is referred to the scientific description ; it is enough here to say 

 that the flowers are of two kinds, male and female, the two kinds often on different 

 plants, more seldom on the same, and still more rarely on the same part of the 

 same plant. The male blossom, whose contents correspond to stamens, is some- 

 times cup or properly cactus shaped, and it is conspicuous on the various species 

 of Polytrichum, or hair-moss ; in this instance its brilliant orange and crimson cups 

 being very like ordinary flowers. The female blossom, enveloped in the sheath 

 (or perichcetvm) , has a body answering to the pistil, and this in time will pi'oduce 

 the seed-vessel, the parts of which are the stalk (seta) supporting the seed-vessel 

 itself [capsule) . This, in its early stages, is covered with an extinguisher-shaped 

 veil (calyptra) , which is generally like a thin semi-transparent membrane; but in 

 the Polytrichum (hair-moss) family is clothed with silky golden filaments, and in 

 the Orthotriclmm (bristle-moss) tribe is beset with upright hairs. As the 

 contents of the capsule become larger it expands, and in most cases the calyptra, 

 becoming split and torn, then falls off, but in a few mosses it is permanent. 

 The division of the calyptra may take place at the side, or all round it, or it may 

 be irregular ; but so perfect is the " order of the universe," even in things so 

 minute and apparently unimportant, that the calyptra always splits in the same 

 manner on the same species of moss. The veil gone, the capsule is revealed, its 

 most common form being that of a bird's head, but it is often round, as in the 

 Bartrammia (apple-moss) group, and urn-shaped, as in the hair-mosses. The 

 mouth is generally closed by a lid (operculum) , which has often a beak, and when 

 the seed is fully ripe the lid generally falls off, and it is scattered. Sometimes, 

 however, the capsule has no removable lid, and the seed then escapes through the 

 bursting of its sides. The lid gone, we generally find the mouth of the capsule 

 still farther guarded by a single or double row of hairs ; these are the fringe 

 (peristome) . When the fringe is present it takes a variety of forms ; but in 



