Successive leaves isolated from the gametophore exhibit differences in the number of regenerates obtained per organ. Starting from the base, successive leaves show an increasing number of regenerates per leaf. This pattern is similar in leaves isolated from young and older gametophores, although the younger ones show a much greater absolute number of regenerates.No correlation exists between the number of cells per organ and the number of regenerates. Although the size of the wound surface plays an important part in the number of regenerates produced, this factor cannot determine the regenerative pattern between successive leaves.Correlative factors are shown to exist in individual leaves and the distribution of regeneration in the leaf is determined also by these factors.It is concluded that the age of the organ determines the regular pattern of protonematal regeneration of successive organs.