In the fall of i906 the writer enjoyed the privilege of examining the extensive collection of tropical aroids in the greenhouses of the New York Botanical Gardens, and of collecting material for an investigation of the embryo sac and embryo. Among other species, Nephthytis Gravenreuthii was selected for this purpose. A considerable amount of material was obtained, illustrating stages from the archesporium to the mature embryo. OVARY.-The genus is characterized by a single simple carpel which shows a tendency toward a slightly unsymmetrical development, the stylar canal never being in the axis of the carpel (fig. 2). The carpel is short and thick, the stylar canal very short, funnelshaped, and lined with viscid conducting cells. On the interior of the carpel the conducting cells reach a considerable length and come in contact with the ovule on all sides, sometimes reaching quite to the micropyle. OVULE.-The ovary contains a single, basal, anatropous, cauline ovule. Probably the single, basal, orthotropous ovule is the most primitive kind, and in Arisaema we find an orthotropous ovule, but there are typically four ovules; and while they are cauline in origin they occur as lateral outgrowths of a suppressed placenta, the illdefined point of the placenta representing the axis of the flower. The single axial ovule, even though it be anatropous, is no doubt a simpler type than this; and when we compare it with such a form as Dieffenbachia, in which each ovule, arising from the partially suppressed placenta, is surrounded by a separate carpel, its primitive character becomes yet more apparent. In general, the ovule of the species now under discussion is peculiar for its massive integuments and for the poor development of the nucellus. The latter consists at first of a single row of cells sur35] [Botanical Gazette, vol. 46