The gender semantics of Worora (a non-Pama-Nyungan language of the Kimberley region of northern Australia) is examined, and linguistic and cultural explanations are sought for the categories observed. An opposition is uncovered in the nonhuman macrogender between intensions that refer underlyingly to the earth, on the one hand, and to the sky, on the other. The formal and functional properties of the system are then compared with those of Nunggubuyu, a non-Pama-Nyungan language of eastern Arnhem Land. On the basis of this comparison, a historical explanation is suggested to account for the typological similarities observed.