In a recent Number of the Geological Magazine Mr. Burns assumes that Geologists in general seem to be satisfied with Mr. Croll's theory of the motion of glaciers because they do not write in refutation of it. I am convinced that with some at least it requires no refutation, and its very obvious inadequacy is to them a sufficient reason for passing it over in silence. There cannot be wanting men who, appreciating the difficulty of the problem, can only smile at such a “solution.”