It is pointed out that there are 2 distinct schools of thought regarding the inheritance of sex. Is sex inheritance dependent upon a single pair of factors in the sex-chromosomes or is its expression due to a number of factors located in the autosomes and functioning in cooperation with the pair of factors carried by the sex-chromosomes? The author challenges the evidence presented by Bridges (1932) in substantiation of the latter view. The data given by Bridges are carefully analyzed and the conclusion reached that they "do not quite bear out the author''s contention." There follows a brief discussion of the point of view of the "modifiers," to which group Punnett belongs, and that of the "Drosophilists.".