Introduction . The questions here involved are many and various, and their consideration carries us from one place to another over a very wide area. We cannot safely draw inferences as to the age and origin of any drifts on the borders of a mountain-land without, on the one hand, tracing it up to the source from which it was transported, to see whether we can explain the distribution of the various kinds of matarial of whie]l it is composed, and, on the other hand, following it as far as possible down over the lowlands, to see whether any succession of deposits or organic remains or evidence as to its former extent can be made to throw light on the conditions of the age in which it was distributed. And, seeing that most caves have been formed and filled during the age of accumulation of the various superficial deposits which we include under the name “drift,” we cannot safely speculate upon the age or origin of the one set of phenomena without considering all the evidence to be derived from the other also. Only in the hilly districts can we find caves at all, and, generally, the more important occur along the outskirts of the high lands, where drifts of various character are apt to be found. The relation of the local drifts to the caves may be of great interest if the exact place and age of those drifts have first been clearly made out. We must first therefore inquire