Although chromatographic profiles and amino acid compositions of erythrocyte histones from normal and regenerating goose blood did not differ, characteristic fractions from regenerating blood contained more alkali-labile phosphate than did their counterparts from normal blood. Furthermore, the phosphate content of the erythrocyte-specific component was appreciably greater than that of any other histone.The problem of distinguishing between contamination and valid histone phosphate is considered; complex formation between nuclear phosphoprotein and specific histone fractions could not be unequivocally eliminated. The pronounced phosphate levels in the erythrocyte-specific histone V are discussed in relation to the prospective roles of histone phosphorylation.