A variety of aberrant erythrocyte forms have been related to seven adult and two fetal hemoglobins in white-tailed deer. While sickling of the erythrocyte was not associated with a single hemoglobin type, it was precluded by hemoglobin V or VII, even when in combination with other hemoglobin types normally associated with sickling. The subunit basis of the hemoglobin polymorphism was presented. Two kinds of α subunits, six kinds of β subunits and one γ subunit were related to the whole hemoglobin molecule. The heterogeneity of the deer hemoglobins was based upon a variety of combinations of these numerous polypeptide chains. It was concluded from the results of limited structural studies that there were multiple peptide differences upon comparison of three non-α polypeptide chains.