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

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