CELL-CONTENTS AND FORMS OF CELLS. 177 



petals of certain lilies, where we find some cells of a deep purple 

 color, others of a deep red, and still others of intermediate shades 

 These substances are easily extracted with water or dilute alco- 

 hol and are all more or less affected by certain chemicals (many 

 of which occur naturally in the plant), such as citric acid, oxalic 

 acid, salts of calcium, iron, aluminum, etc. 



Fig 104. Microcrystals formed in Kava-kava, the mot of Pi/^cr victln'sticum : 

 ^, crystals ot methysticin obtained on treatment of sections of the root" or the 



p (iiuite 

 ysticin can 



acohol and allowing the slide to stand for 24 hours. Crystals of methvM.L,.. can 



also be obtained upon sublimation, providing the powder has been acted on' previously 



IV \^ , u*^- sulphuric acid, emulsin, or saliva.— After Tunmann in Gehe & Co.'s 

 -tlandelsbericht, 1912. 



A number of plant pigments of this class are used as indi- 

 cators in volumetric chemical analysis, their use in this connection 

 being dependent upon their sensitiveness to acids and alkalies. 

 The fact that they respond to iron salts, — that is, give a blue or 

 green reaction with these salts, — would indicate that they are 

 associated with tannin or that they are tannin-like compounds, as 

 has been supposed by some writers, but they behave very differ- 

 12 



