BRITISH MOSSES. 



23 



never enters upon that generation at all. This is epito- 

 mized in the second column, under the head " Moss," of 

 table B. 



The Tetraphis pellucida is one of our most lovely little 

 Mosses ; it grows in hollows in woods, and on damp and 

 decaying stumps of trees, and produces 

 capsules comparatively rarely at least I 

 have only once found the capsules growing 

 but relies mainly for its reproduction on 

 gemmae not much different from those of 

 the Orthotrichum, but these it carries in 

 cups at the end of its stem, formed of 

 large, delicate and almost translucent 

 leaves, which with their egg-like gemmae 

 are a very beautiful structure. A magni- 

 fied drawing of this Moss forms our Fig. 11. 



The Aulacomnium palustre is another 

 British Moss which is reproduced sometimes 

 by spores, sometimes by gemmaa, but in 

 this case the gemmae are borne, not on the 

 ends of the leaves or in terminal cups, but in 

 clusters growing at the ends of special 

 supporting stalks growing out from the plant laterally. 

 The two forms of the plant, the spore-bearing and the 

 gem-bearing, are strangely unlike as regards their general 

 appearance, and the casual observer would, I feel 

 sure, take them for widely different plants. The 

 question whether the plant shall adopt the one mode 

 of reproduction or the other seems to depend, in part 

 at least, on temperature, a high temperature tending 



FIG. 11. Te- 

 traphispellu- 

 cida, with its 

 cup contain- 

 ing gemmae, 

 after Schim- 

 per. 



