The colloidal nature of starch, and the high molecular weight of the complex has rendered it impossible to study the constitution of this polysaccharide by other than degradation reactions. Accordingly starch has been hydrolysed in various ways to give dextrins, amyloses, maltose or glucose, according to the method adopted, and the stage at which the reaction was arrested. […] Improved methods of separation have enabled the constitution of those partially methylated glucoses to be fully worked out in the present research, and in this way the order in which methyl groups enter the molecule has been traced. The main programme of the research may therefore be synopsised as under: 1. Attempts to degrade starch by mild ‘acetolysis'. 2. A comparative study of the methylation of starch before and after acetylation. 3. A complete study of the partially methylated glucoses obtained from methylated starch. 4. Determination of the order in which methyl groups enter the starch molecule. 5. The graded hydrolysis of methylated starch.