NEWTON E. MORTON University of Wisconsin RECENTLY SEVERAL INVESTIGATORS have reported that the genes for elliptocytosis and the Rh system may be closely linked (Goodall et al., 1953, 1954; Lawler and Sandier, 1954; Marshall et al., 1954). Other studies, however, did not suggest linkage (Chalmers and Lawler, 1953; Hollander, 1954; Fujii et al., 1955; Vandepitte and Louis, 1955). The data on this subject are unusually extensive, and they provide strong evidence of an autosomal linkage in man. Since these pedigrees also exemplify some of the difficulties encountered in the study of human linkage, it may be profitable to analyse them more closely.