924 



IX. MUSCL 



\'A^\ 



Alrichum undulatum. 

 Peristoinium (mag.). 



Fontinalis antipyretica. 

 Peristomium (mag.). 



Dawsonia polytrichoides. 



Filiform peristomium 



(mag.). 



»»» 



Cinclidotus ripariits. 



Portion of peristominm 



(mag.). 



fiuxbaumia aphylla. 

 Peristomium (mag.). 



3ODdSb5D0 



Ortholrichum stramineum. 



Portion of peristomium 



(mag.). 



Cinclidium s/ygium, 

 Peristomium (n ag.). 



Entosthodon fascicularis. 



Vertical section of capsule 



(mag.). 



Funaria liygrometrica. 

 Germinating spores (mag.). 



of very A'arious form ; the fibrous cells are larger, very thin, hyaline, filled with a watery 

 liquid and amylaceous granules ; the medullary cells are narrower and thicker, but 

 soft and brownish ; they contain no granules, but colour by iodine. 



EooTS. — The roots spring either from basilar cells or from peripheric cells of the 

 stem ; they are always composed of a single series of cells united by oblique walls ; they 

 are more or less branched, the principal branches of a reddish brown, the branchlets 

 white or hyaline. In many species a resinous exudation forms a granular deposit on 

 their surface, which is of great importance in attaching certain species to hard bodies ; 

 in other cases contributing to the agglutination of sands and the binding of the dunes 

 on sea-coasts by tufted species {Polytrichum piliferum, nanutn, Barbula ruralis, Rha- 

 comitrium canescens, &c.). Besides their subterranean roo,ts, most Mosses possess 

 aerial or adventitious roots, which are developed over the whole surface of the stem, 

 but more especially in the axils of the leaves of the branches. 



Leaves. — Blade usually simple, nerveless, or traversed longitudinally by one, 

 rarely by two, cellular bundles {Hylocomium), commonly termed nerves, which may 

 be shorter than the blade, or may reach its apex, or extend beyond it as an awn, 

 bristle or hair-point. In some species the nerves present on the upper or lower 

 surface more or less regular excrescences {Fissidens, Pottia), or plates with thickened 

 margins {Barbula, Polytrichum). The leaves are always sessile, and inserted more 

 or less horizontally [or obliquely or longitudinally], often decurrent, with usually 

 symmetrical wings ; and are distichous or alternate, and arranged in regular spirals. 



