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that are found in the green algae as well as in leaves and that came, 

 undoubtedly, from the green algae within the thalluso Other species 

 of lichens with blue=green algae within the thallus would be expected 

 to yield the pigments characteristic of the blue-green organismso The 

 stonewort, which is classified as a green alga , yielded the pigments 

 which are common to flowering plants, ferns, mosses and most green 

 algae o (See Appendix IVo) 



Chloroplast Pigments of Green Algae (Chlorophyta) 



The green algae have long been regarded as representative of an- 

 cestors common to their line and to the higher forms of green plants »„ 

 The occurrence of the principal leaf pigments in all green algae lends 

 further support to this viewo 



Mth respect to pigments, the green algae have now been found to 

 fall into two principal groups. The species of one group contained 

 the same pigments found in leaves, often plus traces of a xanthophyll 

 that was adsorbed between the neoxanthin and the violaxanthin in the 

 sugar coliminso The species of the second group contained the pigments 

 characteristic of higher plants plus an additional xanthophyll, siphon- 

 axanthin, and its ester, siphonein '^ '9, as indicated in Figure II, 5o 



The algae of the first group included one species of the one order 

 Charales in the class Charophyceae, and they included many species in 

 nine of the twelve orders in the class Chlorophyceaeo These species 

 are tabulated in Appendix IVo 



The green algae containing s iphonaxanthin and siphonein belonged 

 to the order Siphonales of the class Chlorophyceaeo They included 

 representatives of the five principal families shown in Appendix Vo 



