256 



PLANT RELATIONS. 



cient to protect against a period of drouth. In the tropical 

 forest there is danger neither from cold nor drouth, and in 

 such conditions bud scales are not developed, and the buds 

 remain naked and unprotected. 



(6) Devices against too abundant rain. — The abundance 

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



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 gut- 

 ter-pointed, that is, the tip 

 is prolonged as a sort of 

 gutter, and the veins are 

 depressed, the whole sur- 

 face of the leaf resembling 

 a drainage system, so that 

 the rain is conducted rap- 

 idly from the surface (see 

 Fig. 214). These are only 

 a few illustrations of many 

 devices against dangerous 

 wetting. 



B. Deciduous or mon- 

 soon forests. — In these for- 

 ests the same general habits prevail as in the rainy evergreen 

 forests, but to a less degree. For example, the epiphytes 

 and lianas are present, but they are not so numerous or 

 conspicuous. The striking difference, however, is the 



Fig. 214. A gutter-pointed leaf from a 

 tropical plant.— After Schimper. 



