CONTENTS 



Xlll 



Section 52. Buds and branches 



A. Kinds of buds 



B. Overproduction of buds 

 Section 53. Accumulation in stems . 



A. Why not " storage " ? 



B. Substances accumulated 



C. Latex .... 

 Section 53 A. Forestry 



A. Importance of forests 



B. Aims of forestry 



C. Forestry outside of forests 



PAGE 



185 

 186 

 189 

 190 

 191 

 192 

 193 

 195 

 195 

 195 

 196 



CHAPTER SIX: LEAVES 



Section 54. Introductory . 201 



A. Use and beauty of leaves 202 



B. Points already noted 203 



Section 55. External characteristics ' . 204 



A. Venation 204 



B. Shape 206 



C. Attachment and arrangement .... 208 



D. Leaf surfaces 212 



E. Leaf size and foliage area 215 



Section 56. Functions 219 



A. Transpiration 219 



B. General relation of water to the plant . . . 224 



C. Respiration 225 



D. Photosynthesis 228 



E. Summary as to gaseous exchanges . . . 233 

 Section 57. Structure 234 



A. Epidermis 234 



B. Stomates 235 



C. Mesophyll 237 



D. Veins 240 



vSection 58. Protection 241 



A. The shedding of leaves and their autumnal colors 242 



B. Movements of leaves 247 



C. The edgewise position ....... 249 



Section 59. Special forms of leaves 251 



A, Needle-like leaves 252 



B. Leaves as insect traps 252 



