POWDERED DRUGS 721 



a In rosette-shaped crystals. Continued. 



2. Crystals not less than 10 ^ in diameter. 

 * Pollen grains numerous. 



Crystals numerous 173. Caryophyllus 



Crystals few. 174. Insect Powder 



** Pollen grains few. 

 t Ducts present. 



Glandular and non-glandular hairs. . 175. Cusso 

 ft Ducts wanting. 



Stone cells few 176. Viburnum Opulus 



Stone cells numerous. 



177. Viburnum Prunifolium 



/3 Calcium oxalate in monodinic prisms. 



1. Numerous seeds. 



Characteristic odor 178. Vanilla 



2. Seeds wanting, 



Stone cells few 179. Viburnum Opulus 



Stone cells numerous, characteristic. 



180. Viburnum Prunifolium 

 Numerous oil globules 181. Xanthoxylum 



7 Calcium oxalate in crystal fibers. 



Stone cells characteristic 182. Quercus Alba 



6. Calcium oxalate wanting. 



a Containing pollen grains. 



Non-glandular hairs numerous 183. Arnicse Flores 



Spherical pollen grains 184. Crocus 



Non-glandular hairs few v . . . 185. Santonica 



/3 Pollen grains wanting. 



1. Stone cells numerous. 



Fragments wine-colored with sulphuric acid. 



186. Cubeba 



Characteristic stone cells 187. Delphinium 



Green fluorescence in chloral mount. 



188. Stramonii Semen 

 Ducts reticulate 189. Pyrethrum 



[ ,.: 



2. Stone cells wanting. 



Non-lignified intermediate fibers 190. Gentiana 



Few fragments of tissues 191. Opium 



Tracheae with elongated, narrow pores. 



192. Taraxacum 



Tracheae with large, simple pores 193. Chicory 



Ducts spiral, annular or with simple pores. 



194. Triticum 



