32 



CHAPTER VI. 



HABITATS OF MOSSES. 



In speaking of the nature of Mosses (p. 5) we have already 

 mentioned the sorts of situations and conditions under which 

 they occur. While many are almost indifferent to their place 

 of growth, whether on rocks or branches of trees, or on the 

 ground, others are confined to a peculiar matrix, as those 

 Splachna which require for their nutriment either the dung 

 of an herbivorous or carnivorous animal, or the Mosses which 

 affect some especial kind of rock — whether siliceous, as An- 

 dreace, or calcareous, as Seligeria ealcarea (Plate 24, fig. 2) or 

 Encalypta streptocarpa — for their nutriment or growth. Sand- 

 stone caves seem the peculiar requisite of Schistostega. A 

 few Mosses seem to flourish peculiarly upon straw roofs, as 

 Tortula ruralis (Plate 22, fig. 4), but they are by no means 

 confined to such a situation. The decaying thatch merely 

 supplies a richer nourishment than usual, exactly as it does to 

 Agaricus furfur aceus and A. siipitarius, which are finer in such 

 situations than elsewhere. 



Elevation however has no" less influence on the occurrence 

 of various species. While some are almost ubiquitous, we 

 should in vain seek for Conostomum boreale (Plate 15, fig. 8), 

 Polytriehum sexangulare, or Pogonatum alpinum, at low alti- 



