The investigation reported in this thesis was concerned with a series of mutations at the waxy locus in maize. Dr. Barbara McClintock who provided the original material used in this thesis also gave the explanation of the genetics behavior of the mutation inducing Ac-Ds system (14). The waxy mutants which occurred in this material were isolated and identified by starch-lodine titrations. The mutant starches identified in two or more selfed generations covered a range of amylose percentage from the waxy type to the starchy type. Three intermediate mutants produced starch calculated to contain 20, 9 and 3.42 percent amylose;Gene dosage effects of the starchy, waxy and three intermediate types were studied in a series of reciprocal crosses. The effects on starch properties were analyzed by means of the sample iodine titration values, viscosity readings end gal strength measurements. The reciprocal crosses showed that of two alleles, the one which conditioned the higher amylose content was partially dominant over the other. The female parent in reciprocal crosses had greater effects than the male;The method of selection of presumed mutants was expected to minimize the frequency of intermediate mutants. Likewise the number of mutants at or near the starchy and waxy types was expected to be high. The number of intermediate mutants found was higher than either extreme type. This unexpected result may have been the effect of an accumulation of mutations which occurred before the sampling took place. The appearance of these intermediate mutants was in contradiction to the hypothesis of Sager (17) that metabolism conditioned by the waxy locus acts as a phenotypic filter through which new allele do not pass. The homogeneous nature of the starch granules of these mutant types provided a sharp contrast in physical properties of the starch pastes to the heterogeneous mechanical mixtures. The viscosity and gel strength measurements for the gene dosage samples and for the mechanical mixtures were interpreted in terms of the swelling of the starch granules.