1 6 Living and Dead Matter and 



2. That such a solution can serve for the synthesis 

 of all the compounds of living yeast cells is due to the 

 fact that it contains the sugars. From the sugars 

 organic acids can be formed and these with ammonia 

 (which was offered in the form of ammonium tartrate) 

 may give rise to the formation of amino acids, the 

 "building stones" of the proteins. It is thus obvious 

 that the synthesis of living matter centres around the 

 sugar molecule. The phosphates are required for the 

 formation of the nucleins, and the work of Harden and 

 Young suggests that they play also a role in the alco- 

 holic fermentation of sugar. 



Chlorophyll, under the influence of the red rays of 

 light, manufactures the sugars from the CO 2 of the air. 

 This makes it appear as though life on our planet should 

 have been preceded by the existence of chlorophyll, 

 a fact difficult to understand since it seems more natural 

 to conceive of chlorophyll as a part or a product of 

 living organisms rather than the reverse. Where then 

 should the sugar come from, which is a constituent of 

 the majority of culture media and which seems a pre- 

 requisite for the synthesis of proteins in living organ- 

 isms? 



The investigations of Winogradsky on nitrifying, 1 

 sulphur and perhaps also on iron bacteria have to all 

 appearances pointed a way out of this difficulty. It 



1 Winogradsky, S. f "Die Nitrification," Handb. d. tech. MykoL, 1904- 

 06, iii., 132. 



