220 



PLANT ORGANS OR PARTS OF PLANTS. 



ular hairs with one-celled stalk and two to four-celled 

 heads and large oil and resin glands are very abundant. 

 On section, the palisade tissue is twice as thick as the 

 spongy tissue; both are rich in calcium oxalate. A 

 horseshoe-shaped woody pith is contained in the midrib, 

 consisting of radially arranged vascular channels. The 

 perianth carries glands and long, thin-walled hairs. 



Fig. 6o.— Cannabis Indica. 



oed, Oil glands; tr, hairs; d, young gland; a, b, c, d, e^f, g, developing 



gland; p, protoplasm in trichome; k, crystals. 



Powder. — This is a dirty, brownish-green, and when 

 moistened and pressed is sticky. It contains a large 

 number of histological elements, inasmuch as stem, leaf, 

 flower, and seed constituents enter into the powder. 

 The main histological features are hairs, glands, pollen 

 grains, crystals, resin, parenchyma, epidermis, fibres, 

 vessels, and stone cells from the seed. The hairs alone 

 are diagnostic of the powder. There are two or three 



