TRANSPIRATION, 159 



Grasses (Glyceria aquatica, Phalaris arundinacea), 

 Sedges (Carex stricta), and Knot-weeds (Polygonum 

 ampliibium). It is a pretty sight to see one of 

 these leaves held under water. The whole under 

 surface shines like quicksilver, and however we 

 may shake and turn the leaf, we cannot dislodge 

 its covering of air. When we take it out of the 

 water this side of the leaf is quite dry, while the 

 other is wet. Stomata are also found on stems, 

 but they are not so numerous as on leaves. 



Some kinds of trees may have a great effect in 

 transferring water from the soil to the atmos- 

 phere. The Eucalyptus tree is the most useful 

 for this purpose, and is often planted in order to 

 drain marshy places. 



