where Caldwell had left it. It may be that, before doing so, we have to verify his statements in the light of the later advance made in the methods of philological study. For example, it is now generally recognized that sounds constituting speech should be studied not simply from their accoustic standpoint but also from the organic point of view. The organic study of sounds is, in fact, more important for the scientific philologist than their accoustic aspect. The transition of sounds in combination with others is a phenomenon that can be studied only by the observation of the movements which the speech organs undergo in producing them. Thus, the scientific philologist is no longer satisfied with statements like the euphonic perumtation of consonants or euphonic nunnation. To say that a change has been effected for the sake of euphony is not no explanation at all, but only a device to escape out of a philologi-
