Leafy Mosses 



and branches break off and are blown hither and thither by 

 the wind, each piece being capable of growing into a new plant, 

 if it has moisture long enough to permit it to get well started. 

 It can then endure long periods of drought and can avail itself 

 of small quantities of moisture which may be condensed from 

 the air. 



It must be remembered that normally all plant food is manu- 

 factured by the green colouring matter in the leaves and stems of 

 plants, and that these little agents can work only in the light. 

 The light must not be too weak, or the leaf-green becomes yellow 

 and cannot work; again the light must not be too strong or the 

 leaf-green is destroyed and the water in the plant is too rapidly 



evaporated, with the result that 



the plant dies. 



In order that moss plants 



may avail themselves of small 



quantities of water and may 



Polylrichum commune. Summit of spore- 

 case showing membrane surrounded with 

 sixty-four teeth. 



Apex of leaf to show 

 entire margin. 



Catharinea undulata. 

 Tip of spore-case with 

 thirty-two teeth at- 

 tached by their tips to 

 a membrane. 



Octoblepharum 

 albidum. Spore- 

 case with eight 

 teeth. 



Spore-case. Part of peristome. 



Ulota HiilchinsuB. 



Aulacomnium heterostichum. Leaf apex 

 to show serrate margin. 



33 



