SUMMARYA case of twin nucelli in an ovule ofPterocarya fraxinifolia, originated from a cleavage of the nucellus primordium and presumably representing a hitherto unrecorded type of polyembryony inJuglandaceae, is discussed. The qualification of this category of polyembryony as “false polyembryony” according to the conventional classification of Ernst is unsatisfactory. A new system of classification of polyembryony is propo