In 1920 Minot and Weld,1 working in this laboratory, examined for iso-agglutinins 160 specimens of blood from the umbilical cord obtained from the Boston Lying-In Hospital. They found that by testing both the serum and cells of these specimens against the cells and serum of all four groups that the groups could be established in 70 per cent, of these new-born infants. Their success in grouping this percentage of new-born infants seems to have due to a careful technic, and the recognition of weak agglutination. Because of the wide variation of their results from those reported by others, Minot suggested that I repeat this study and make certain further observations.
Most of the important advances in the knowledge of iso-agglutination have been made from studies of adult blood, and for this reason it is necessary to review some of these articles in this paper. The first important observations on