466 



BOTANY OF THE LIVING PLANT 



will arise from the rhizoids already there. If leaves or stems be 

 chopped up, any undamaged cell may grow out under favourable 

 circumstances into protonema, giving rise to a new crop. But 

 besides this, in many Mosses certain parts are so developed during 

 normal life that they are readily detached as gemmae, which may start 

 new colonies in fresh stations. The protonema itself may break into 

 short lengths (Funaria), or bulbils may be formed upon it (Barbula) 

 (Fig. 356, B), or gemmae may be formed on the surface of the leaves 



Fig. 360. 



Leaf -gemmae of Aidacomnion palustre. 

 The drawing shows the gemmae, and scars 

 where some have been shed. (F. O. B.) 



Fig. 361. 

 Meesia uliginosa, Hedw. (After 

 Hedwig, 1787-) Showing antheridia 

 (an), and archegonia (ar), with para- 

 physes (/>), on same axis. 



(Grimmia), or in terminal cups (Tetraphis). Whole leaves, slightly 

 modified for the purpose, may sometimes be detached, as in Aula- 

 comnion palustre (Fig. 360). In any case protonema is formed first, 

 and subsequently Moss-Plants as buds upon it. 



Frequently it is by suctumeans that Mosses are spread. But a more 

 certain transfer to longer distances is by the minute spores produced 

 in the capsule, or sporogonium, which thus reveals itself as the sporo- 

 phyte generation (Fig. 355). This like other sporophytes results from 

 propagation by sexual organs borne by the gametophyte. The 

 antheridia and archegonia of Mosses are sometimes borne on the ends 



