INTRODUCTION xiii 



from the pentoses are of the same types as those produced from 

 the hexoses. The order in Table j is product^ substrate^ organism^ 

 anthorityy enabling the reader to find the types of substrate 

 from which a given chemical has been reported as produced by 

 the named organisms. At the end of the paper is given the list 

 of references cited. It is the hope of the authors that this 

 treatment, limited as it is, may be of value ingiving an adequate 

 key to the literature on the chemical changes produced by 

 microorganisms acting on non-nitrogenous organic compounds. 



