Fig. 2. Isolated chromatophores. Negative staining with neutral phosphotung- 

 state. A. From cells of 3-day-old culture of RJiodospirillum molischianum 

 comparable to those in Fig. 1. B. From cells of 2-day-old culture of Rhodo- 

 spirillum rubrum grown anaerobically in the light. Length of black bar rep- 

 resents 0.1^. 



