represented by _i_ L _d_ and _l_ S _e_ and _n_ W _f_, respectively; in Fig. 4, _i_ conducts only sound-excitations coming from L, _l_ only excitations coming from S, and _n_ only those coming from W, as impulses for M. For the present, I see no way of deciding between the two possibilities. They may even exist both together. All the following statements concerning the localization of the disturbances of speech and the parallel imperfections of child-speech apply indifferently to either figure; it should be borne in mind that the nerve-excitement always goes _only_ in the direction of the arrows, never in the opposite direction, through the nervous path corresponding to them. Such a parallel is not only presented, as I have found, and as I will show in what follows, by the most superficial exhibition of the manifold deviations of child-speech from the later perfect speech, but is, above all, necessary for the answering of the question: what is the condition of things in learning to speak? [Illustration: FIG. 4.] 3. Parallel between the Disturbances of Speech in Adults and the Imperfections of Speech in the Child. In undertaking to draw such a parallel, I must first of all state that in regard to the pathology of the subject, I have not much experience of my own, and therefore I rely here upon Kussmaul's comprehensive work on speech-disturbances, from which are taken most of the data that serve to characterize the individual deviations from the rule. In that work also may be found the explanations, or precise definitions, of almost all the names--with the exception of the following, added here for the sake of brevity--skoliophasia, skoliophrasia, and palimphrasia. On the other hand, the statements concerning the speech of the child rest on my own observations of children--especially of my own son--and readers who give their attention to little children may verify them all; most of them, indeed, with ease. Only the examples added for explaining mogilalia and paralalia are taken in part from Sigismund, a few others from Vierordt. They show more plainly (at least concerning rhotacism) than my own notes, some imperfections of articulation of the child in the second year, which occur, however, only in single individuals. In general the defects of child-speech are found to be very unequally distributed among different ages and individuals, so that we can hardly expect to find all the speech-disturbances of adults manifested in typical fashion in one and the same child. But with very careful observation it may be done, notwithstanding; and when several children are compared with one another in this respect, the analogies fairly force themselves upon the observer, and there is no break anywhere. The whole group into which I have tried to bring in organic connection all the kinds of disturbances and defects of speech in systematic form falls into three divisions: