Development of the Ovulate Strobilus and Young Ovule of Zamia Floridana

Abstract

1. The young staminate and ovulate strobili can be distinguished by the difference in breadth, number of sporophylls, and number of meristematic points. 2. There is probably a single archesporial cell giving rise to a group of cells, one of which becomes the megaspore mother cell. 3. There are four potential megaspores, the lowest one becoming the embryo sac, whose development agrees with the accounts of other cycads in the main points. 4. The spongy tissue is an active, nutritive tissue, adding to its width by division of its cells as it is encroached upon by the embryo sac. 5. In its final degeneration, the cells of the spongy tissue nearest the embryo sac are first attacked, and the smaller cells outside them take their place, becoming large, swollen, and nutritive in function.