WITCHES BROOMS OF CHERRIES 241 



The leaves chosen had but a trace of green color. The alcoholic 

 .extract was a brownish green color. This extract was in turn 

 treated with benzol. The resulting benzol phase was red in 

 color while the alcoholic portion was left a green color. This 

 evidently indicates that chlorophyll is present but is merely 

 masked by the red pigment. This condition is to some extent 

 analogous to that found in the Phaeophyceae and Rhodophy- 

 ceae, where a brown or red pigment may partially or entirely 

 mask any green coloration that may be present. 



The red color is greatly intensified if the benzol phase be 

 slightly acidified. Mineral and organic acids have the same 

 effect. When treated with potassium hydroxide or other alka- 

 lies a brownish green color results. The solution on being again 

 acidified becomes a deep red. 



These facts naturally lead to the assumption that the red 

 color of the leaves is due to an indicator which is red in acid so- 

 lution. To demonstrate this point the following simple tests 

 were made. First the benzol phase was tested with litmus. It 

 was acid in reaction. Secondly branches of the brooms which 

 had equally red leaves were placed in water, slightly acid, and 

 slightly basic solutions. The twigs placed in pure water re- 

 mained unchanged after twenty-four hours. Those standing in 

 the slightly acid solution had the red color in the leaves greatly 

 intensified while those in the shghtly basic solution had the red 

 color considerably diminished. If, however, the twigs of the 

 brooms were left standing in water for longer periods of time (one 

 week) the red color gradually disappeared. 



Practically the same experiments were tried with the leaves 

 from the normal twigs. These had but a slight red color in 

 rare cases. The benzol phase of the alcoholic extract was light 

 3^ellow in color although it turned an intensive red on being 

 acidified. The yellow solution was neutral towards litmus. 



A very large broom was also found on the native wild cherry 

 {Pi'uniis emarginata) . A similar red color, although not so 

 evenly distributed through out the leaf, was found in the leaves 

 of the infected area. Alcoholic and benzol extracts showed the 

 presence of the red coloring matter with similar properties to 

 those previously discussed. 



