74 OUTLINES OF BACTERIOLOGY 



the power of utilising their colouring matter in the same way as the 

 green plants make use of their chlorophyll, viz. to absorb carbon 

 dioxide from the atmosphere, making use of the energy of the sun's 

 rays for this purpose. The name bacterio-purpurin has been given 

 to the colouring matter of the purple bacteria. 



In later chapters, these groups of bacteria will be dealt with in 

 greater detail. 



