16 POWDERED VEGETABLE DRUGS 



5 5 Contents. Sometimes diagnostic (some species of 



jaborandi). 



5 4 Air chamber. Never diagnostic. Crystals of calcium 

 oxalate usually more numerous in the spogny 

 tissue cells bounding the air chamber. 

 2 1 Hypodermal elements. Usually wanting and rarely of any 



significance, especially in powders. 

 I 2 Upper hypoderm. 



1 3 Size and form of cells. Larger than those of lower hypoderm. 

 2 3 Number of cell layers. Usually two. 



3 3 Cell walls. Colorless and comparatively thin. Mucilagin- 

 ous in buchu. 

 4 3 Contents. Usually empty. 



I 4 Cystoliths in large cells (Ficus). 

 2 4 Mucilage. 



3 4 Crystals of calcium oxalate. 

 2 2 Lower hypoderm. Compare with the upper. 

 3 1 Palisade tissue. Never characteristic in powders. 

 I 2 Size and length of cells. 

 2 2 Rows of cells. One to three. 

 3 2 Contents. 

 I 3 Chlorophyll. 

 2 3 Crystals. Not usual. 

 4 1 Spongy tissue. Rarely characteristic. * 



I 2 Form of cells. 

 I 3 Oval and elongated. 



2 3 Branching. 

 2 2 Contents. 



I 3 Coloring matter. Not usual. 

 2 3 Crystals. Prismatic and aggregate. 

 3 3 Resin, wax, inulin, tannin. 

 4 3 Chlorophyll. 



5 1 Stone cells in leaf parenchyma. Rare but diagnostic (tea). 

 6 1 Mechanical cells. Usually not diagnostic. (Eriodictyon, lateral 



lines of coca). 



7 1 Glands. Not characteristic in powder. 

 I 2 Form. 



2 2 Contents. Resin, wax, coloring matter. 

 3 2 Number. 



4 2 Position in leaf parenchyma. 



8 1 Leaf stalk (petiole). Structure usually not characteristic, 

 similar to that of stem. 



