248 PLANT RELATIONS. 



of rain is in danger of checking transpiration, and as tliis 

 process is essential to plant activity, there are often found 

 devices to prevent the leaves from becoming saturated. 

 Many leaves have cuticles so smooth and glazed that the 

 water glances off without soaking in ; in other cases a 

 velvety covering of hairs answers the same purpose ; in 

 still other cases leaves are gutter-pointed, that is, the tip 

 is prolonged as a sort of gutter, and the veins are depressed, 

 the whole surface of the leaf resembling a drainage system, 

 so that the rain is conducted rapidly from the surface (see 

 Fig. 203). These are only a few illustrations of many 

 devices against dangerous wetting. 



