VEGETABLE POWDERS 



417 



I. |.. .TT....I.. .71. .. .!....!.. ..I.... I....1 

 Scale in Micron*. 



Fig. 137. MENTHA PIPERITA. 



a. Upper epidermal cells. 



b. Lower epidermis. 



c. Trichomes, simple, showing cuticular markings (a medium sized trichome). 



d. Gland, top view. 



e. Small glandular trichome. 



