During the course of breeding Papilio memnon we have managed to investigate the genetics of four unique forms. Two, affecting adult pattern, we had previously speculated to be the result of crossovers within the supergene controlling mimicry in this species. The present investigation shows them in fact to behave as 'allelomorphs' of the supergene. Furthermore, the dominance relations of the five elements of the pattern are those which must pertain if the forms do result from a crossover, thus supporting our hypothesis. The other two, a larval colour mutant (blue) and an adult eye colour mutant (pink), have been shown to be controlled by autosomal recessives. Both are unlinked to the supergene. The absence of linkage would be expected since there would have been no selection for a linked condition.