I have read with much interest Mr. Reid's paper on the Glacial Deposits of Cromer. It is a valuable contribution towards the elucidation of a difficult subject. I cannot, however, think that at present the mode of accumulation of glacial deposits is finally settled. The old people, among whom I count myself, used to consider these heterogeneous mixtures to have been dropped from floating-ice, or to have gone down, ice and all, to the bottom of the sea, when so much of the ice had been thawed that the mineral matter exceeded one-twentieth of the whole bulk. Now, however, many of the younger geologists, and especially those connected with the Survey, attribute much more importance to the action of great glaciers or ice-sheets, enveloping not only whole countries, but also filling up and advancing over what are at present sea-beds.