A substantial obstacle to current medical and surgical progress is the established fact that tissues and organs from one person transplanted to another will not survive. Although it has been suspected that rejection of homografts has an immunologic basis, proof of this concept is lacking. Bruton, in 1952, first described a child suffering from agammaglobulinemia. Since this original report, about 30 patients with agammaglobulinemia have been studied and the characteristic features of this disorder have been defined. All of the children thus far described as suffering from this syndrome are males; all show extreme susceptibility to bacterial infection, absence of gamma globulin from the serum, absence of known antibodies, including natural isohemagglutinins, from the serum, and failure to respond to antigenic challenge with antibody production. Thus, in these children, nature has produced a virtually complete "immunologie paralysis." Agammaglobulinemia, with the associated failure of the immune response, has also been discovered