136 MOSSES AND LIVERWORTS 



hygroscopic (i.e. are easily affected by the 

 presence of water), they help to bring about the 

 bursting of the capsule wall; another believes 

 that their duty consists in loosening the masses of 

 spores at the time when the capsule opens ; while 

 others have thought that their sudden uncurling, 

 at the moment when the restraint exerted by the 

 closed capsule wall is removed, helps to scatter 

 the spores. Whichever of these theories is the 

 correct one and they all, probably, contain some 

 amount of truth it seems to be generally agreed 

 that the elaters are concerned with the escape of 

 the spores from the capsule. As a rule, they fall 

 with the spores, but occasionally some of them 

 may be found clinging to the empty capsule ; thus 

 in fig. 17 of Plate IX., which represents the open 

 capsule of that little tree-loving plant, the 

 Tubercled Liverwort (Frullania dilatata), the 

 curious screw-like elaters are seen standing out 

 from the sides of the capsule in all directions. The 

 fruit of this plant is sometimes, but by no means 

 always, produced in considerable abundance, and 

 when this is the case the small, white, empty 

 capsules are very noticeable, dotted about among 

 the dark green or purple foliage; they form 

 extremely beautiful objects for the microscope, 

 with their dainty fringes of elaters, and my 

 drawing does but scant justice to the charm of the 

 original. 

 Reproduction otherwise than by Spores, The 



