The alteration undergone by the Coniston Flags, owing to the intrusion of the Shap granite, has been well and fully described by Messrs. Harker and Marr in their most able and interesting paper, read before the Geological Society in the spring of this year, “The Shap Granite and the Associated Igneous and Metamorphic Rocks” (Q.J.G.S. vol. xlvii. 1891).I have worked a great deal, microscopically, on the rocks of this district, both before and since the publication of the results of Harker and Marr, and this work has enabled me in a special manner to appreciate the quality and value of their investigations in this complicated and interesting region. I was so fortunate, two summers ago as to spend some time at Shap with Mr. Marr, who most kindly assisted me to understand some of the problems involved, and pointed out to me the places where specimens of special interest could be collected.