Most people who have lived in strongly glaciated countries are familiar with the topographic features known as drumlins. They are more or less elongated hills of boulder-clay with their long axes parallel to the direction of ice-motion. The literature dealing with them is extensive, but for the most part rather unsatisfactory. Their mode of formation is entirely a matter of speculation and is likely to remain so. There is every reason to believe they are deepseated products of the ice, so that observation of the process in modern ice-sheets is impossible. The only available means of getting at the truth is by careful observation of the peculiarities of form and structure exhibited by these features in the areas where they are most characteristically developed.