76 NATURE TEACHING. 



hairy coatings, so arranged that those parts of 

 the leaf which are abundantly provided with 

 pores are extremely difficult to wet, while 

 surfaces with few pores are wetted easily. 

 Good instances of this are seen in bamboo 

 leaves which are easily wetted on the upper 

 surface where there are no pores, but which 

 throw off water from their under surfaces in a 

 wonderful manner. The leaves of water-lilies 

 cannot be wetted on their upper surfaces but 

 the under surfaces live in constant contact 

 with water. 



6. It is interesting to observe how the 

 leaves of plants, by their position and arrange- 

 ment, throw, in different directions, the water 

 which falls on them as rain. In many young 

 plants, as for example tobacco, cabbage, or 

 beet, the leaves are so arranged that all the 

 water which falls on them is directed towards 

 the centre of the plant, and flows down the 

 stem moistening the ground near its base, 

 where, at an early stage of growth, the young 

 rootlets are to be found. As the plant grows 

 the leaves often bend downwards at the tops 

 while still inclined inwards at the base. 

 There is thus a division of the rain, a portion 

 flowing towards the stem and a portion to- 

 wards the outer boundary of the plant, a 



