286 



DISTRIBUTION OF SPORES 



The spores are freed by the forcing off of a circular lid, the 

 operculum, as is the case among the majority of the mosses 

 (Fig. 203, 0). This is effected by a ring of thin-walled cells, 



Fig. 204. 



Fig. 204. Germination of the spore of Sphagnum: A, early growth of 

 the spore. B. later development — sp, spore; b, bud developing into moss 

 plant. C, margin of the thallus, showing the origin of the bud. — After Camp- 

 bell. 



Fig. 205. The twisted stalk moss, Funaria: A, two sporophyte-bearing 

 plants, the remains of the archegonium or calyptra still attached to the cap- 

 sule on the right. B, enlarged view of plant with the young sporophyte, 

 still enclosed in the archegonium, just emerging above the leaves. C, the 

 male plant bearing the antheridia in a conspicuous rosette of leaves. D, 

 upper portion of the sporophyte, showing the twisting of the stalk or seta 

 that assist in sifting the spores through the teeth, peristome, that encircle 

 the m.outh of the capsule. 



the annulus, that lies in the groove just below the operculum. 

 As the walls of the capsule dry out at maturity they shrink, 

 compressing the air vvith'n the capsule until the tension ruptures 



