124 CAROTINOIDS AND RELATED PIGMENTS 



Carotinoid-forming bacteria afford an excellent opportunity for 

 fixing the conditions under which these pigments develop and thus 

 throwing some light on the true functions of carotinoids in plants. 

 The growth of these plants is subject to very exact laboratory con- 

 trol and their pigmentation is not complicated by the formation of 

 chlorophyll. 



