The antigen-binding cell clones and the Ig-positive cells were found and quantitatively assessed in the primary hemopoietic splenic colonies. The data ogtained were analyzed assuming that the ratio of clone of specialized B-cells should reflect the quantitative ration in the corresponding V-genes in the given lymphocyte populations at definite stages of its development. The colonies differed from one another markedly by the curves of inhibition by DNP-lysine of rosette-formation with DNP-erythrocytes, i.e. by the avidity of B-cells of the given specificity. The colonies differed significantly by the ratio of the volumes of the two clone groups (cell with anti-DNP and anti-BE Ig-receptors) between themselves and the combination of the Ig-positive cells. These quantitaive regularities were incompatible with the view that each B-cell had any conceivable set of V-genes, i.e. with the germ-line hypothesis of the antibody and receptor diversity.