58 MOSSES. 



give the patches of the moss a hoary appearance on 

 wall-tops. The margins of the leaves are folded back 

 or recurved, giving them a peculiar thickened ap- 

 pearance. 



The largest of our mosses are contained in the 

 next genus, viz. Polyt'richum, some of them having 

 the stems from 2 to 4 inches, or even more, in height ; 

 they are common on heaths and in woods. 



Polyfrichum piliferum (PL III. fig. 22) is very 

 common on open dry heaths. This moss has simple 

 stems, with the leaves crowded on the lower part of 

 those which are fertile or fruit-bearing. The fruit- 

 stalk is terminal (acrocarpous) ; the capsule ovate, 

 4-sided or quadrangular, with a knob or struma 

 (struma, a swelling) at the base, the lid having a 

 short beak. The calyptra (fig. 24) is half-cleft (di- 

 midiate) and very hairy. The peristome is single, 

 and consists of sixty-four teeth. The leaves (fig. 23) 

 are lanceolate, nearly upright, the margins folded 

 inwards or inflexed ; and they end abruptly in a saw- 

 edged or serrated hair-like point. 



Poly'trichum commune, which is also very common, 

 is larger than the last species, and may easily be dis- 

 tinguished by the curved and serrate leaves, which 

 have no bristle-point. 



In the early spring, patches of both these mosses 

 may be found, in which the stems are terminated by 

 little rosettes (figs. 25 & 26) ; these will be referred 

 to presently. 



Keeping still to the end-fruited or Acrocarpous 

 mosses, we have next to mention Funaria hygro- 

 met'rica (PL III. figs. 28, 29), which is readily dis- 

 tinguished from most other mosses by the pale apple- 

 green colour which it possesses before the capsule 

 ripens. It is extremely common on walls and waste 

 ground. 



The capsule of this moss (fig. 31) differs from 

 those of the preceding mosses in the peristome being 



