A second example of an unusual B gene, named B3 by Moullec, has been presented, with a family study. Absorption and elution tests and studies of the saliva of a mother and her daughter established this group as a genetically determined subgroup of B. In our opinion, the substance found in the saliva of these individuals and of so called "aberrant secretors" of groups A2 and A2B may be so specific as to require their specific cell types in order to demonstrate their presence or absence.