The genetics of short branch and cluster fruiting habit of cotton were studied in experimental lines containing these traits. The material used consisted of six cl, type, three long branch type G. hirsutum L. lines, and one cl(2) G. barbadense L. line. These types represented the three branching habits of normal (Cl(1)Cl(1)Cl(2)Cl(2)), cluster (cl(1)cl(1)cl(2)cl(2)), and short branch (Cl(1)Cl(1)cl(2)cl(2)). Crosses were made in all possible one way combinations and their F₁'s selfed in order to determine the segregation patterns in the F₂ populations. The recessive cluster gene (cl(1)) found in G. hirsutum L. results in pronounced shortening of the sympodia. The short branch gene (cl(1)) found primarily in G. barbadense L. results in tip clustering. There were differences between the progenies produced by the different G. hirsutum L. cl(1) lines in both the F₁ and F₂ population indicating possible variation in modified gene action. In one particular interspecific cross, the F₁ was uniform throughout with both long branching and fruit tip clustering, a result of incomplete recessive gene expression due to modifiers. The results indicate that there are a number of discrete types in the short-branch habit and cluster-fruiting habit of Gossypium spp.