1. Imperfections not occasioned by disturbance of the intelligence--pure speech-disturbances or _lalopathies_. 2. Imperfections occasioned solely by disturbances of the intelligence--disturbances of continuous speech or discourse (Rede)--_dysphrasies_. 3. Imperfections of the language of gesture and feature--_dysmimies_. I. LALOPATHY. A. THE IMPRESSIVE PERIPHERAL PROCESSES DISTURBED. _Deafness._--Persons able to speak but who have become deaf do not understand what is spoken simply because they can _no longer_ hear. The newly born do not understand what is spoken because they can _not yet_ hear. The paths _o_ and _a_ are not yet practicable. All those just born are deaf and dumb. _Difficulty of Hearing._--Persons who have become hard of hearing do not understand what is spoken, or they misunderstand, because they _no longer_ hear distinctly. Such individuals easily hear wrong (paracusis). Very young infants do not understand what is spoken, for the reason that they do _not yet_ hear distinctly; _o_ and _a_ are still difficult for the acoustic nerve-excitement to traverse. Little children very easily hear wrong on this account. B. THE CENTRAL PROCESSES DISTURBED. _Dysphasia._--In the child that can use only a small number of words, the cerebral and psychical act through which he connects these with his ideas and gives them grammatical form and syntactical construction in order to express the movement of his thought is _not yet_ complete. (1) The Sensory Processes centrally disturbed. _Sensory Aphasia_ (Wernicke), _Word-Deafness_ (Kussmaul).--The child, in spite of good hearing and sufficiently developed intelligence, can _not yet_ understand spoken words because the path _m_ is not yet formed and the storehouse of word images W is still empty or is just in the stage of origination. _Amnesia, Amnesic Dysphasia and Aphasia, Partial and Total Word-Amnesia, Memory-Aphasia._--The child has as yet no word-memory, or only a weak one, utters meaningless sounds and sound-combinations. He can _not yet_ use words because he does not yet have them at his disposal as acoustic sound-combinations. In this stage, however, much that is said to him can be repeated correctly in case W is passable, though empty or imperfectly developed. (2) The Sensori-motor Processes of Diction disturbed. _Acataphasia_ (Steinthal).--The child that has already a considerable number of words at his disposal is _not yet_ in condition to arrange them in a sentence syntactically. He can _not yet_ frame correct sentences to express the movement of his thought, because his diction-center D is still imperfectly developed. He expresses a whole sentence by a word; e. g., _hot!_ means as much as "The milk is too hot for me to drink," and then again it may mean "The stove is too hot!" _Man!_ means "A strange man has come!"