Reciprocal hybridization experiments were performed between the line of Beltsville Small White turkeys that has been selected for high incidence of parthenogenesis and two strains of chickens. The eggs were examined cytologically at early stages of development. In the cross of turkey females X chicken males, it was found that both male (2A-ZZ) and female (2A-ZW) zygotes are formed, but the latter are much less viable and usually die in a very early stage of development. Besides the hybrid embryos, parthenogenetic-type embryos also were found. In the cross of chicken females X turkey males, no evidence of successful hybridization was obtained. However, cell division was initiated in 100 percent of the chicken eggs. This fact suggests that turkey sperm had some enhancing effect on parthenogenetic cell division in chicken eggs.