FKUCTIFICATION OF MOSSES 671 



cells,' each of which, as it comes to maturity, develops within itself 

 an antherozoid (B, C, D) ; and the antherozoids, set free by the 

 rupture of the cells within which they are formed, make their 

 escape by a passage that opens for them at the summit of the antherid. 

 The antherids are generally surrounded by a cluster of hairlike 

 filaments (fig. 509, A), which are called paraphyses ; these seem to 

 be ' sterile ' or undeveloped antherids. In the ' hair-moss,' Poly- 

 trichum commune, one of the largest of our mosses, common on dry 

 heaths, these antherids are collected into conspicuous starlike 

 clusters at the extremities of tlie branches of the * male ' plants. 

 These are to be seen about April, and at the same time the arc-he - 

 gones may be detected concealed among the leaves on the ' female ' 

 plant ; while the capsules, or sporanges, in this and most other 

 mosses, make their appearance late in the summer, and remain 

 through the winter. The archegones bear a general resemblance to 

 those of Marchantia (fig. 507), and the fertilisation of their con- 

 tained oospheres, or germ-cells, is accomplished in the manner 

 already described. The fertilised embryo-cell becomes gradually 

 developed by cell-division into a conical body elevated upon a stalk ; 

 and this at length tears across the walls of the flask-shaped arche- 

 gone by a circular fissure, carrying the higher part upwards on its 

 summit as a calypter or hood (fig. 508, B, c), while the lower part 

 remains to form a kind of collar round the base of the stalk, known 

 as the vayine. 



The urn, theca, or sporange, which is the immediate product of 

 the generative act, is closed at its summit by an opercule, or lid 

 (fig. 508, B, o, 0), which falls off when the contents of the sporange 

 are mature, so as to give them free exit ; and the mouth thus laid 

 open is surrounded, in many mosses, by a beautiful toothed fringe, 

 which is termed the jteristonie. This fringe, as seen in its original 



FIG. 510. Mouth of sporange of Funaritt, FIG. 511. Double peristome 



showing the peristome in situ. of Fontinalis antipyretira. 



undisturbed position (fig. 510), is a beautiful object for the binocular 

 microscope ; it is very ' hygrometric/ executing, when breathed on, 

 a curious movement which is probably concerned in the dispersion 

 of the spores. In figs. 511-513 are shown three different forms of 

 peristome, spread out and detached, illustrating the varieties which 



