Sunshine, Rain, and Wind 



In the common red loosestrife (Lythrum SaHcaria) the 

 rain falling on the leaf is led down the groove of the stalk, 

 and then by a bold sweeping curve of the leaf base down- 

 wards ; it then runs down the grooved stem and passes 

 over the next bud below, where it is strained through a 

 row of small reddish hairs which intercept all dust. 



In many of the dead nettle order (Mentha aquatica, 

 Galeopsis tetrahit) there is a raised line which connects 

 the opposite leaves and which seems at first to be a use- 

 less ornament. But the water from the leaf-stalks spills 

 across above this line, and its dust is strained out by 

 special rows of hairs. 



Naturally one of the objects of this book is to tempt 

 some readers at least to examine plants for themselves ; 

 these rain gutters and grooves and straining hairs are 

 easy to trace and interesting, for no two systems are 

 alike. That there is useful material to be found amongst 

 the dust is obvious from the small table which follows, 

 and which shows what were actually found in the 

 gutters : — 



Such things as pollen, algae, and spores of all kinds 

 are extremely rich in nitrates, phosphates, and other 



193 N 



