The explanation which the two authors attempt to formulate as the basis of their collection of examples is peculiarly inadequate. They hold that the sounds and syllables of a word have different values and that the innervation of the sounds of higher value can interfere with those of lower value. They obviously base this conclusion on the cases of anticipation and perseveration which are not at all frequent; in other forms of slips of the tongue the question of such sound priorities, even if they exist, does not enter at all; for the most frequent type of slip is that in which instead of a certain word one says another which resembles it, and this resemblance is considered by many people sufficient explanation of it. For instance, a professor may say in his opening lecture, “I am not inclined (_geneigt_ instead of _geeignet_ = fitted) to estimate the merits of my predecessor.” Or another professor says, “In the case of the female genital, in spite of the _tempting_ ... I mean, the _attempted_ ...” (_Versuchungen_ instead of _Versuche_). The commonest and also the most noticeable form of slip of the tongue, however, is that of saying the exact opposite of what one meant to say. These cases are quite outside the effect of any relations between sounds or confusion due to similarity, and in default one may therefore turn to the fact that opposites have a strong conceptual connection with one another and are psychologically very closely associated. There are well-known examples of this sort. For instance, the President of our Parliament once opened the session with the words “Gentlemen, I declare a quorum present and herewith declare the session _closed_.” Any other common association may work in a way as insidious as the association of opposites and may on occasion lead to results as inopportune. So there is a story to the effect that, at a festivity in honour of the marriage of a child of H. Helmholtz with a child of the well-known inventor and captain of industry, W. Siemens, the famous physiologist Dubois-Reymond was asked to speak. He concluded his doubtless brilliant speech with the toast “Success to the new partnership, Siemens and _Halske_!” which was of course the name of the old firm. The association of the two names must have been as familiar to a resident in Berlin as “Crosse & Blackwell” to a Londoner. So the effect of word associations must be taken into account, as well as that of sound-values and similarities between words. But even that is not enough. In one type of case, before we can arrive at an adequate explanation of the slip we must consider some phrase which had been said, or perhaps only thought, previously. Again, that is, a case of perseveration, as Meringer insists, but arising in a more distant source.—I must confess that altogether I have the impression that we are further than ever from comprehension of slips of the tongue.