Green Leaves at Work 97 



minute chlorophyll-bearing seaweeds, which live 

 near the surface of all but the very coldest wa- 

 ters, and are the floating pastures of the sea. 



In plants which habitually bear richly-colored 

 leaves in the copper-leaved beech, for instance, 

 or the copper-hazel chlorophyll bodies are present 

 and busy, just as they are in those plants which 

 bear green foliage ; but the leaf-sap contains some 

 strong pigment which overpowers and masks the 

 green. Some of those minute plants which have 

 a great and evil reputation under the name of 

 bacteria contain a purple coloring-matter which 

 seems able to fulfil the office of chlorophyll. 



By aid of this pigment they can form organic 

 matter when they are exposed to the light. 



A few other bacteria can form organic matter 

 in the dark, and unaided by any pigment, green 

 or purple. 



But such " exceptions being excepted," the 

 vividness of the green in stem or leaf is in direct 

 proportion to the plant's self-helpful activity, for 

 in the vegetable world the very young and the 

 very shiftless are not green. 



But when a plant begins to form habits of 

 parasitism the leaves grow dim, and the more 

 confirmed these bad habits become, the less chlo- 



