CONTENTS Vll 



PAGE 



Forms of hairs 67 



Papillae 67 



Unicellular hairs 69 



Multicellular hairs 72 



Periderm 80 



Cork periderm 80 



Stone cell periderm 85 



Parenchyma and stone cell periderm . 85 



CHAPTER III 



MECHANICAL TISSUES 



Bast fibres 89 



Crystal bearing bast fibres 90 



Porous and striated bast fibres 92 



Porous and non-striated bast fibres 96 



Non-porous and striated bast fibres 96 



Non-porous and non-striated bast fibres 96 



Occurrence of bast fibres in powdered drugs 103 



Wood fibres 104 



Collenchyma cells 106 



Stone cells 109 



Endodermal cells 116 



Hypodermal cells 118 



CHAPTER IV 



ABSORPTION TISSUE 



Root hairs 121 



CHAPTER V 



CONDUCTING TISSUE 



Vessels and tracheids 126 



Annular vessels 127 



Spiral vessels 127 



Sclariform vessels 128 



Reticulate vessels 131 



Pitted vessels 131 



Pitted vessels with bordered pores 131 



Sieve tubes 136 



Sieve plate 138 



Medullary bundles, rays and cells 138 



Medullary ray bundle 139 



The medullary ray 139 



The medullary ray cell 141 



