108 THE BACTERIAL PHOTOCHEMICAL APPARATUS 



Fig. 15. Section of Chlorobium thiosulfatophilum , strain 6CR. The 

 cell wall of this strain does not show the rod-shaped extensions char- 

 acteristic of the strains illustrated in Figs. 12 and 13. The general 

 structure of the cell is very similar to that of C. thiosidfatophilio)/, 

 strain Tassajara. Chlorobium vesicles (Cv), mesosomal element (M). 

 Main fixation, 2 hours, post staining with lead hydroxide. X 120,000. 



Fig. 16. Negatively stained preparation of the main pigmented frac- 

 tion isolated from extracts of C, thiosulfatophilum , strain Tassajara 

 (see text). 



