The study of the action of Aspergillus Niger on sugars and other substrates has received a great impetus in recent years. This work is conveniently summarized by Bernhauer. l Since this fungus thrives particularly well on sugar solu-tions it was thought desirable to investigate its action on a series of homologous substances which resemble a hexose molecule in part of their molecules. We have in the molecule of glucose the grouping CH20HCHOH-in the ...