growth of the pollen tube into the ovule not through the micropyle but through the tissue of the chalaza (the basal part of the ovule). The pollen tube usually grows inside the nucellus and then penetrates the embryo sac in the micropyle portion of the ovule, near the egg cell. Chalazogamy was first described in the Australian pine (Casuarina) in 1891 by the Dutch scientist M. Treub and in the birch, filbert, and alder in 1895 and 1899 by the Russian scientist S. G. Navashin. Subsequently, a number of other scientists described the phenomenon in other plants.