STRUCTURE.] CHKOMULE. 131 



to Link, a power of motion exists in the grains of chlorophyll 

 until a grain of starch is formed within them, when the motion 

 immediately ceases. 



Of Chromule, which is the fluid colouring matter of plants, 

 nothing is known that requires to be mentioned, unless it be 

 that it principally occurs in organs of short duration, such as 

 petals, and that it is, perhaps, never green. " The red fluids 

 rendered blue by alkalies, and the blue reddened by acids, 

 all contain nitrogen, according to Liebig, but not as a base." 

 (Henfrey.} 



K 2 



