MICROSCOPICAL EXAMINATION OF POWDERED VEGETABLE DRUGS 99 



2 3 In groups. 



3 3 Continuous concentric layers. 

 2 2 Size and form. Porosity of walls. 

 I 3 Typical. 



2 3 Very large and short (Cinchona) . 

 3 3 Branching cells. 

 3 2 Contents. Some starch. 

 7 1 Crystal-bearing fibres accompanying bast and stone cells. Quite 



important and diagnostic. 

 8 1 Sclerenchymatous tissue. 

 I 2 Occurrence. 

 I 3 Singly. 

 2 3 In groups. 



3 3 Continuous concentric layers. 

 2 2 Size and form. 

 3 2 Cell-walls. 

 I 3 Porosity. 

 2 3 Thickness. 

 I 4 Uniform. 



2 4 Thicker on one side (cinnamon). 

 3 3 Color. 



9 1 Medullary ray tissue. Radially curved. 

 I 2 Cell-forms. Porosity of walls. 

 2 2 Cell-contents. Starch and crystals. 

 3 2 Number of cell rows. 

 10 1 Epidermal. Quite generally wanting. 



II 1 Chlorophyll-bearing parenchyma. Usually wanting in the 

 older barks. 



V. ROOTS AND RHIZOMES. 



I 1 Epidermal elements. Usually not distinct or wanting. 

 2 1 Cork. Usually typical when present. 

 3 1 Parenchyma. Typical and well developed. 

 I 2 Form of cells. 



I 3 Outer parenchyma tangentially flattened. 

 2 3 Inner parenchyma isodiametric. 

 2 2 Cell-contents. Very important. 

 I 3 Starch granules. 

 I 4 Simple. 



I 5 Form and size. 



2 5 Lamellation. 



3 5 Position of hilum. 



