Abstract
In Cattanach's X-autosome translocation a piece of autosome of linkage group I has been inserted into the X-chromosome and a piece of X may have been reciprocally translocated to the autosome (Cattanach, 1961; Ohno & Cattanach, 1962). The present communication reports investigations to locate the autosomal insertion in the X-chromosome linkage map and provide evidence pertinent to the question of the possible reciprocal nature of the rearrangement; a brief summary of the results has already been reported (Cattanach & Isaacson, 1965).