hole." Indeed, there is no doubt that some of the incorrect notions about subterranean ice formations, are due to the inaccuracy of the terminology. The only language, so far as I know, which has a correct and really generic term for subterranean ice formations, is the French in its word _glacière_. The French and Swiss say _glacières naturelles_ of ice deposits formed naturally underground; and _glacières artificielles_ of ice houses. _Glacière naturelle_ is comprehensive and accurate. It covers all the rock formations and suggests also the mode of formation of the ice. It likewise implies the strong resemblance between natural ice deposits and artificial ice houses. It might be well, therefore, if the French term _glacière_ were adopted as a generic term for all underground ice formations. As, however, there is little likelihood of this happening, the question arises as to the best English equivalent or equivalents. These seem to be "freezing cavern, freezing talus," etc., "natural refrigerator" or "subterranean ice formation." "Natural refrigerator" and "subterranean ice formation" are more generic than "freezing cavern, freezing well," etc.; but the latter have the advantage of suggesting immediately that reference is made to the hollows of the earth which at times contain ice; and, therefore, they are the best terms, perhaps, which can be chosen in English. Another point in the terminology of this subject has reference to subterranean hollows where draughts issue or enter. Such hollows are found in all parts of the world and are known usually in English as "blowing caves" or "cold current caves." The Germans speak of them as _windröhren_ or _windlöcher_. In my first paper about caves,[12] I used the word "windhole" which I translated from the German. The term "windhole" seems to me preferable to "blowing cave" or "cold current cave" in that it is more generic. It applies to taluses or boulder heaps, or in fact, to any hollows where draughts issue or enter, whether these hollows are genuine caverns or not. [12] _Ice Caves and the Causes of Subterranean Ice_, November 1896, and March 1897. It is necessary also to explain here that "glacière" and "windhole" are not synonymous terms. It must be understood that a glacière or natural refrigerator is a place where ice forms and endures in a subterranean or semi-subterranean situation; and that _the presence of ice_ is the criterion of whether a place is or is not a glacière. Likewise it must be understood that a windhole or blowing cave is an underground hollow with at least two openings, and in which distinct draughts occur; and that the _presence of draughts_ is necessary to constitute a place a windhole or blowing cave. A freezing cavern may or may not be a windhole, and a windhole may or may not be a freezing cavern.