A SUITABLE alternative title for the first section of this paper would be “Impossibilities and Geology”. In point of fact it deals more with other matters of a diverse kind than with its own proper subject as implied in the principal heading. The discussion of the theory of continental drift has now reached such a point that it is believed that the setting forth of a few useful analogies may possess some value. It is hardly too much to say that the present status of the controversy is that geological evidence continues to accumulate showing that lateral movement of continental masses has taken place, as is indeed admitted, either directly or tacitly, by many of the opponents of the Wegenerian theory, while mathematicians and cosmogonists continue to reiterate that such is impossible. Now the real meaning of this attitude is that the mathematicians and astronomers have not yet discovered a cause, which is not by any means the same thing as proving that there is no possible cause, a philosophical distinction which is very commonly disregarded. A similar state of affairs has existed several times before, even in some of the more important problems of quite modern geology.