[Primary structure of hemoglobin of the polar bear (Ursus maritimus, Carnivora) and the Asiatic black bear (Ursus tibetanus, Carnivora].

The adult Polar and Asiatic Black Bear have one hemoglobin component each. The complete amino-acid sequences of their alpha- and beta-chains are presented. Their primary structures were determined by sequencing the tryptic and prolyl peptides. The alignment of these peptides was deduced from homology to human hemoglobin chains. The hemoglobin sequences of the two species proved to be identical. The evolutionary aspects of this result are discussed. A table of identical hemoglobin sequences from different species is given.