20 Living and Dead Matter and 



of bacteria which oxidize thiosulphate to sulphuric 

 acid. They will develop if some Na2S203 is added to 

 sea water. These bacteria can only develop if CO 2 

 from the air is admitted or when carbonates are pre- 

 sent. For these organisms the CO 2 cannot be replaced 

 by glucose, urea, or other organic substances. Such 

 bacteria must therefore possess the power of producing 

 sugar and starch from CO 2 without the aid of chloro- 

 phyll. Similar observations were made by Beijerinck 

 on a species of fresh-water bacteria. ^ 



Finally the case of iron bacteria may briefly be 

 mentioned though Winogradsky's views are not accepted 

 by Molisch. 



We may, therefore, consider it an established fact 

 that there are a number of organisms which could 

 have lived on this planet at a time when only mineral 

 constituents, such as phosphates, K, Mg, SO 4, CO 2, 

 and O2 besides NH3, or SH2, existed. This would 

 lead us to consider it possible that the first or- 

 ganisms on this planet may have belonged to that 

 world of micro-organisms which was discovered by 

 Winogradsky. 



If we can conceive of this group of organisms as 

 producing sugar, which in fact they do, they could 

 have served as a basis for the development of other 

 forms which require organic material for their develop- 

 ment. 



* Beijerinck, M., Folia Microhiologica, 1914, iii., 91. 



