CONTENTS xi 



PAGE 



Phloem and Xylem Bundles 160 



Cambium 161 



Medullary Rays 161 



Cell Contents of Roots 162 



Tabulation of Functions of the Root Tissues 162 



CHAPTER XW 



STEM STRUCTURE 



Primary Stem Structures 163 



Arrangement of the Tissues 164 



Characters of the Tissues 166 



Epidermis 166 



Hypodermis 166 



Cortical Parenchyma 167 



Endodermis 167 



Phloem, Cambium and Xylem Tissues 168 



Pith Parenchyma 168 



Cell Contents in Primary Stems ' \ 168 



Tabulations of Functions of the Primary Stem Tissues 169 



Secondary Stem Structures 169 



Changes incidental to the Formation of Secondary Tissues. . . 170 



Bark Structures 170 



Arrangement of the Tissues 171 



Characters of the Tissues 171 



Cork 171 



Phellogen and Phelloderm 171 



Cortical Parenchyma 176 



Medullary Rays 176 



Phloem Elements 176 



Cell Contents in Barks 177 



Wood Structures , 177 



Arrangement of the Tissues 177 



Characters of the Tissues , 178 



Xylem Elements 178 



Medullary Rays 179 



Pith Parenchyma 182 



Cell Contents in Woods 182 



Tabulation of Functions of the Secondary Stem Tissues 182 



Rhizomes 183 



