Fig. 65. 



Absorption Spectra of the Sulphur Bacteria. 

 I. The bacteriopurpurin of Ray Lankester. 

 II. Absorption Bands (after Engelmann). 



III. Bactenochlorin in absolute alcohol (after Molisch). 



IV. Bacteriopurpurin a. in chloroform (after Molisch). 

 V. Chlorophyll. 



VI. -VIII. Thioporphyra volutans. — Three spectra obtained on different 

 days from the same carbon bisulphide extract. 

 IX. Thioporphyra volutans. — Spectrum of coloured extract, taken 

 from culture on cardboard. 

 X. Phycoerythriu. 



