1908] GOW—STUDIES IN ARACEAE 41 
EXPLANATION OF PLATES IV-VI 
PLATE 1V 
Nephthytis Gravenreuthii 
Fic. 1.—Section of tip of ovule, showing massive integuments, small nucellus, 
and two sporogenous cells. 
{G. 2.—Ovary at somewhat later stage. 
Fic, 3.—Three adjoining sections of the same embryo sac, showing eight 
vigorous nuclei and traces of two or three others. 
Fic. 4.—Egg-apparatus. 
Fic. 5.—Antipodals, and endosperm nuclei with incipient wall-formation. 
Fic. 6.—Endosperm at a later stage, proembryo (e), and a persistent 
Synergid (s). 
Fic. 8.—Second proembryo in same sac shown in Jig. 6. 
Fic. 9.—Proembryo. 
Fic. 10.—Embryo showing notch. 
Fic. 11.—Mature embryo. 
Fic. 12,—Fertilization, showing pollen tube (p), egg (0), male cell (m), 
and synergid (s), 
PLATE V i 
: Dieffenbachia daraquiniana 
Fic. 13.—First appearance of carpels. 
Fic. 14.—Later stage. 
Fic. 15.—First appearance of ovule. 
Fic, 16.—Later Stage, showing nucellus (7) and integuments (i, 0). 
Pie. £9.—Section of ovary, showing stigmatic surface (st), stylar canal (5s), 
and the anatropous ovules. : 
Fic. 18.—Section of ovule showing an embryo sac containing endosperm 
nuclej (e); the other structures are evident. 
1G. 19.—The archesporial cell. 
Fic. 20.—Division of epidermal cells. 
5 21.—The linear tetrad, the outermost megaspore (m) functional. 
IGS. 2 
F 
Fic. 27—Fusion of male cell with endosperm nucleus. 
Fic. 28 —Free endosperm nuclei. 
Fic. 29.—Endosperm at later stage, and proembryo. 
Figs. 3°-32.—Early divisions in proembryo-formation. 
PLATE VI 
Aglaonema versicolor 
BE FIG. 33.—Ovary with the solitary ovule; embryo sac containing embryo (¢), 
dosperm (%), and antipodals (a). 
