MOSSES 71 



two mosses so much resemble each other that it is 

 frequently a matter of great difficulty, in the 

 absence of fruit, to distinguish them. But if the 

 ripe capsules happen to be present no such 

 difficulty arises. For, while in the one case 

 (fig. 8), the teeth of the peristome, when highly 

 magnified, are seen to be marked with a delicate 

 net-work of lines, in the other (fig 6) this net- 

 work is absent, and we have only the ordinary 

 transverse bars, with a curious zig-zag line down 

 the centre of the tooth, caused by the shape of the 

 ends of the cells of which it is formed. 



In many cases there are two sets of teeth, an 

 outer and an inner peristome, which, of course, 

 constitute a still further check on the escape 

 of the spores. Plate IV. fig. 11, and Plate V.a, 

 fig. 10, where the ends of the capsules of two of the 

 Feather-mosses are given, offer good examples. In 

 both cases the drawing has been made from a dry 

 specimen, because then the teeth of the outer 

 peristome are rolled over, so as to disclose the 

 inner fringe. At fig. 11 of Plate V.a will be 

 found what is, perhaps, the most beautiful 

 peristome of all our British mosses, namely, that of 

 the Greater Water-moss (Fontinalis antipyretica), 

 which, as implied by its name, grows in water. 

 Its long stems, clothed with the curious pointed 

 leaves, each one with the two sides folded 

 together down the centre, in the manner so 

 peculiar to the plant, may be met with in streams 



