“…Included were examples of antiserums for the 1, 3, 7, 8 and 9 antigens [4], antiserums defining the 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 7c, 7d, 8a and 9a antigenic deter minants [3] and Ke, DeR, and Pa serums Suspensions of red blood cells (RBC) were prepared from citrated whole blood. Thirty-one blood specimens, obtained from persons whose leukocytes (WBC) had been typed previously, were mailed to New York from Paris and Leiden.…”