The anterior speech zone is concerned with the motor elements of speech and may also show some degree of morphologic asymmetry, although no unequivocal data have yet been produced. The development of speech in the human infant represents a powerful convergence of neurological and psychological mechanisms, some of which are already in operation long before the birth of the child. The marked increase in numbers of higher order branches on the left side relative to the right suggests enhanced dendritic growth activity at a time when the beginnings of internalization and conceptualization mark the onset of language competence in the child. It is certainly of more than passing interest that an apparent preponderance of dendritic tissue on the nondominant side is gradually lost as speech function commences. Three measures of dendritic structure were of particular interest: the total dendritic length, average segment length and the average number of dendrite segments.