This paper is primarily a review of others previously published. The cellular antigens which distinguish the Pearlneck dove (Streptopelia chinensis) from Ring dove (S. risoria) have been separated into approx. 10 parts in the progeny of baekcrosses to Ring-dove. All or nearly all of 7 of these antigenic characters are found in a 3d species, Senegal (S. sencgalensis). and only a part of 2 of the, remaining 3. A segregation of antigens in Pearlneck serum, in contrast to that of Ring dove, has also been noted in the backcross offspring, as well as in the progeny of backcross to Senegal of hybrids between Pearlneck and Senegal. There appeared to be a minimum of 3 such antigens peculiar to Pearlneck, but not necessarily the same antigens, within each of these back-cross populations. Thus the blood of Pearlneck differs from that of Ring dove in the effects on cellular antigens of genes on about 10 chromosomes, and on serum antigens by effects of genes on a minimum of 3 chromosomes. Out of a probable total of 30 pairs of chromosomes, about 13 chromosomes carry genes with antigenic effects peculiar to the species as compared with Ring dove. However, there are 3 chromosomes of Pearlneck with effects distinguishing the cells of Pearlneck from those of Senegal, and the same number with effects on antigens of the serum. Although previous tests have not been conclusive in settling the question of the existence, of differences between the scrum antigens of individuals within a species, recent observations on human serum have indicated that the serums of some humans may be distinguished from those of others.