ABSTRACT
Mankind has always been puzzled by the phenomenon of growth–the gradual changing of a seed into a plant, of a child into a man. The original belief was that the completed flower existed from the beginning within the seed from which it unfolded, impelled by some mysterious power. From this belief were developed by analogy the expressions ‘development’ and ‘evolution.’ The need of deriving the observable variations of speech from its development has apparently been felt by most of the writers on the subject since they preface their observations on disorders of speech and voice by a survey of normal speech development. The nervous system is the fundamental unit with which we have to deal in our investigations into language and speech, as it is this system which governs the actions of the whole body. In localising, the speech therapist will be well advised to form a very clear picture of the various strata and their interrelations.
