PERISTOME AND SPORES OF MOSSES. 



375 



springing from the outer, and the other from the inner, of two 

 layers of cells which may be distinguished in the immature capsule 

 (Fig. 182, c, p) ; hut one or other of these is frequently wanting 

 at the time of maturity, and sometimes both are obliterated, so 

 that there is no peristome at all. — The number of the ' teeth ' is 

 always a multiple of 4, varying from 4 to 64 : sometimes they are 

 prolonged into straight or twisted hail's. — The Spores are contained 

 in the upper part of the Capsule, where they are clustered round 

 a central pillar, which is termed the Columella. In the young 

 Capsule the whole mass is nearly solid (Fig. 182, c), the space (I) 

 in which the spores are developed being very small ; but this 

 gradually augments, the walls becoming more condensed ; and at 

 the time of maturity the interior of the capsule is almost entirely 



Fig. 186. 



Fig. 187. 



Double Peristome of Bryum 

 intermedium. 



Double Peristome of Cinclidium 

 arcticum. 



occupied by the Spores, in the dispersion of which the Peristome 

 seems in some degree to answer the same purpose as the Elaters of 

 Hepaticae.— The development of the Spores into new plants com- 

 mences with the rupture of their outer walls and protrusion of their 

 inner coats ; and from the projecting extremity new cells are put 

 forth by a process of out-growth, which form a sort of Confervoid 

 filament (as in Fig. 193, c). At certain points of this filament its 

 component cells multiply by subdivision, so as to form rounded 

 clusters, from every one of which an independent plant may arise ; 

 so that several individuals may be evolved from a single spore. 

 A numerous aggregation of Spores may be developed, as we have 



