recipients and acceptance of allografts can be made. The authors have the experi ence and ability to bridge the entire field of transplantation and their article encompasses both clinical and immunochemical data in this area. Their data show clearly that matches for the DR antigens are more important than those at the ABC loci in determination of graft survival. Additional relevant factors, in cluding autoimmunity and other B-cell antigens, are discussed and correlated with graft survival. The authors also present pathology data concerning the distribution of HLA-DR antigens in various...

In 1897, Ehrlich suggested that natural preformed receptors from the surface of cells provided immunity to various chemical substances. Many years later, in 1940, Pauling proffered the concept that antibodies comprised a single poly- peptide chain and that each end of the protein could form an antigen-binding site. Burnet tried to explain the diversity of antibody specificity by hypothesizing that it was cell-derived. These hypotheses probably have led to as much or more experimentation and discussion than any other of the many conjectures set forth to explain immunity on a molecular and...