316 THE DISCOVERY OF THE CHILD words which interest suggests to him and which he is keen to fix by means of graphic language. He breaks out into writing, writing at once whole sentences and not only words detached one from the other. DEFECTS IN LANGUAGE DUE TO THE LACK OF EDUCATION Defects and imperfections in speech are derived in part from organic causes consisting of malformations, or pathological altera- tions of the nervous system; but they are partly connected with functional defects acquired during the period when speech is deve- loping, and they consist of a wrong pronunciation of the sounds composing the spoken word. Such errors are picked up by the child when he hears the word pronounced badly, or hears imperfect speech. Dialect defects come under this heading, but there also •enter into it bad habits, which are responsible for the persistence in the child of defects natural to infantile speech. Again, the •child imitates the faulty speech of the people who surround him in early childhood. The normal defects of childish speech are to be traced to the fact that the complicated muscular apparatus of the organs of •speech is not yet functioning properly, hence it is not able to reproduce the sound which was the sense-stimulus of this internal movement. The association of the movements necessary for the articulation of the spoken word is established gradually. This results in a speech in which sounds are imperfect and often left *out (hence incomplete words). These defects are grouped together .under the term blaesitas* and are mainly due to the fact that the child cannot yet control the movements of the tongue. They comprise principally: sigmatisjn, or the imperfect pronunciation *of the letter S; rhoticism, or excessive use of jR; lambadism, or defective pronunciation of L\ gammacism, wrong pronunciation of <j; lotacism, imperfect pronunciation of the gutterals; mogilalia, 'imperfect pronunciation of the labials; according to some authors, x Defective speech.