From reflex to muscular control in the assumption of an erect posture and ambulation in the human infant.

specie as that period when the animal began to stand and walk erect. Comparably, the transition from infancy to early childhood in the growth cycle of the individual is conveniently determined by the age at which the child begins to stand erect and walk alone. The fundamental principles governing these changes and modifications in the infant's acquisition of walking are essentially the same as the principles governing all behavorial growth in infancy and probably throughout life. The emergence of standing and walking ability on the part of the infant has ever been of extensive general interest but in recent years it has assumed considerable scientific significance since it is claimed that