POWDERED DRUGS AND FOODS. 



749 



90. ASPIDIUM. Light brown or light greenish-brown 

 (Figs. 2'j'^; 285, B ; 2gy) ; starch grains numerous, elHpsoidal, 

 ovoid, oblong and irregularly shaped, varying in length from 2 to 

 18 fx.; numerous small oil globules seen in chloral mounts; 

 tracheae long and with scalariform and reticulate thickenings, the 

 cells being 25 to 75 jx in width. The tracheae are colored reddish- 

 violet on the addition of concentrated sulphuric acid, the reaction 

 resembling that of lignified cells with phloroglucin ; few reddish- 

 brown epidermal cells are present, and the strongly lignified cells 







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Fig. 298. Ltipulin: a-h, successive stages in the development of the glandular hairs 

 on the bracts and floral envelopes of Humulus; g, longitudinal section through a mature 

 hair as seen at h; i, glandular hair with the cuticle raised due to the accumulation and 

 pressure of the oily secretion beneath it. After Holzner. 



of the hypodermis resemble the libriform cells in higher plants. 

 Many of the cells of the parenchyma contain nuclei which may 

 be differentiated by the use of iodine green or methyl green. 



** Fibrovascular Tissue Wanting. 



91. CAMBOGIA. Bright yellow; sternutatory; containing 

 few or no starch grains. ' Not more than 25 per cent, should be 

 insoluble in alcohol, arid the ash should not be more than 3 

 per cent. (p. 648). 



92. LUPULINUM. (See No. 222.) 



93. LYCOPODIUM. Light yellow; spores tetrahedral, deli- 

 cately reticulate, 25 to 40 yu, in diameter (Fig. 278b). 



