60 MOSSES AND LIVERWORTS 



plants naturally have a much less upright habit, 

 and are far more given to creeping on the 

 surface of the ground and to branching out 

 in various directions. Hence it comes about 

 that they commonly have a somewhat feathery 

 appearance, from which fact it arises that 

 so many of them are known as "Feather- 

 mosses." 



The Lid. The mouth of the capsule is usually 

 closed by a tiny cap known as the lid (operculum) . 

 Plate III. fig. 21 represents the capsule of that 

 frequent tenant of the woods, the Swan-neck 

 Thyme Thread-moss (Mniuni hornum), and here 

 the lid is in position on the end of the capsule, 

 while at fig. 22 the lid of the same moss is given 

 after it has been removed. The lid may be either 

 blunt, as in the instance just cited, or it may 

 have a pointed end. And this pointed end may 

 vary, from the very small one shown in fig. 4 of 

 Plate IV.b, to the distinctly beaked lid in fig. 5, 

 or the still longer one in fig. 6. (See also figs. 

 20 and 23 of Plate III.) Or, once more, the 

 whole lid may be long and tapering, as in Plate 

 III. fig. 15, which shows the capsule and lid 

 of our old acquaintance the Wall Screw-moss 

 (Tortula muralis), the lid itself being drawn at 

 fig. 26. In this latter case, as we shall see, 

 when we come to speak of the fringe of teeth 

 round the mouth of the capsule, the form of the 

 lid is necessitated by the peculiar construction of 



