Part 2
a distinct epidermal layer, and very early a sub-epidermal cell becomes distinguishable by its size as the archesporial cell. This soon divides into an apical and a sub-apical cell. The former was found in all cases examined (Fig. 1), though Guignard (’82) states that this is not always true, but the number of anticlinal walls by which it is cut to form the tapetal layer seems to vary. Indeed it soon becomes im- possible to distinguish between the cells of this layer and adjoining ones of the nucellus. The sub-apical cell, or embryo-sac mother-cell, divides twice, thus producing a row of three cells (Figs. 2, 3). As in other plants, it is the lower cell of the row which forms the embryo-sac. The development of the ovule proceeds in normal fashion. The outgrowth soon begins to turn upon itself and assume its anatropous form. At about the time of the division of the archesporial cell, the limit of chalaza and nucellus is indicated by the formation of periclinal walls in certain cells of the 6 Flumphrey.— The Development of the epidermal layer (¢. ¢., Fig. 1), which usually form a double row encircling the base of the nucellus. The growth thus begun is continued so that a ridge of tissue results, which finally encloses the whole nucellus except at the micropyle, forming the inner integument of the ovule (2. 2, Figs. 2, 3, 4). This coat is usually, as in all the Scitamineae studied, two cells in thickness. It begins to be formed slightly earlier on the outer side of the ovule than on the side turned toward the funiculus (Fig. 1). As its development progresses, and when it has reached perhaps half of the height of the nucellus, there arises in the same manner from the epidermal cells just at its base the outer integument. This has a thickness of several cell-layers, as in all the Scitamineae examined, and, at the time of fertilization is of about the same height as the inner integument, so that the long and narrow micropyle is formed wholly by the latter (Fig. 4). The outer integument is in- terrupted by and fused with the raphe as in other anatropous ovules. Meanwhile the vascular bundle has developed in the funiculus, and downward to the chalaza of the ovule. The embryo-sac at first lengthens slightly with the growth of the nucellus, and then rapidly broadens at its micropylar end, destroying the tissue lying between itself and the nucellar epidermis, and acquiring the clavate form which it has at the time of fertilization (Fig. 4). At this time, however, not all of the nucellar tissue is suppressed ; but the sac is separated from the nucellar epidermis by one or more cell-layers, except at its apex. The nucellar and chalazal portions of the ovule are now about equal, and the lower end of the embryo-sac has already penetrated into the chalaza. The fusion of the polar nuclei to form the endosperm-nucleus (esp. 2., Fig. 4) and the developed egg-apparatus (egg) have been observed, but the antipodal cells were not well seen. In view, however, of Guignard’s observations (’82) of the usual phenomena within the embryo-sac of Canna, it was not thought necessary to pursue the subject in detail. The mature ovule is so far turned upon itself that its micropyle lies almost in contact with the funiculus, and the course of the pollen-tube is neces-