As the result of pregnancy immunization two Rhaegative women produced anti-D and anti-LW, while an Rh-pasitive woman produced anti-LW in response to transfusion. T h e 6rst two were both initially LW-negative and direct antiglobulin test negative. One then became direct antiglobulin test positive, and this lasted as long as anti-LW was present in her plasma Other observationa suggest thii may not be a rare occurrence.tests, and an antibody that reacted by saline, albumin, Low's papain and indirect antiglobulin tests with all Rh-negative cells but not at all with Rh..,, cells. We assumed its specificity to be anti-LW. Her cells, which were direct antiglobulin test negative, did not react with anti-LW by Uw's technic. We classed her as LW-negative with anti-D and anti-LW in her serum. No further tests were done at that time.Fourteen months later, her cells reacted strongly with anti-LW by Liiw's technic, and her Serum no longer contained anti-LW. She entered her fourth pregnancy a year later; during it her anti-D titer rose to 1:2,048. Anti-LW did not develop and her red blood cells remained LW-positive and direct antiglobulin negative.

An antibody, anti‐Wiel, defining an antigen, Wiel, in the Rh system, was found in the blood of a white woman who had been sensitized by transfusion and possibly by pregnancy. The inheritance of the antigen was studied in two families, one white, the other Negro. In them it was transmitted by cDue or ℛo In one family this could be refined to cDac(d)e or ℛo ac(d). It was also found in the blood of an unrelated, white woman whose phenotype was R1cdr or Rh1cdrh and in that of an unrelated Negro whose phenotype was R1r. The antigen was not found on testing 2,600 random bloods, nearly all from Caucasians. It is thought it may prove to be less rare in Negroes.

For some time, anomalous serological reactions have been observed when the same anti-Swa sera are tested against red cells from different individuals reported as Sw(a+). A comparative collaborative study using the same collection of Sw(a+) cells and anti-Swa sera was undertaken by 4 reference laboratories, and it was found that Swa represents a heterogeneous group of antigens that can be subdivided into two categories. Both categories, Sw(a+) 700:41 and Sw(a+) 700:-41, were shown to be inherited.

Summary Data are presented which indicate that the Radin blood group antigen is governed by a locus, for the present called Rd, which is located between PGM1 and αFUC Rh, and is either very closely linked to or identical with Sc.