2o8 



SULPHUR BACTERIA 

 MIYOSHI'S TABLE. 



The -\- sign indicates a movement towards, the — sign a movement 

 away from, the source of stimulus. 



different to all these substances. Further, Rhodospirillum 

 giganteum is attracted, but Chromatium repelled, by sulphur- 

 etted hydrogen (concentration not stated). He also established 

 the important fact that for every reacting substance there is a 



