1915] MICHELL—STRIGA LUTEA 135 
16. WETTSTEIN, R. R. v., Handbuch der systematischen Botanik. Leipzig 
und Wien. rogrtr. 
EXPLANATION OF PLATES VIII AND IX 
Abbreviations: mmc, megaspore — cells; int, integument; , nucellus; 
dm, degenerating megaspores; , polars; syn, synergids; amt, antipodals; 
e, egg; pt, pollen tube; 0, oospore; ch, ee Oe Wicetocieni: emb, embryo; 
end, endosperm; s, suspensor; i, haustorium. 
PLATE VIII 
Fic. 1.—Young ovule showing the megaspore mother cell and the origin 
of the integument; 1210. 
IG. 2.—Megaspore mother cell with the nucleus in synapsis; X 1470. 
Fic. 3.—Homotypic division of the megaspore mother cell nucleus; 
Fic. 4.—Ovule showing the embryo sac and three degenerate megaspores; 
Fic. 5.—Binucleate embryo sac; X 1210. 
Fic. 6.—Division of the two nuclei; 1210. 
Fic. 7.—Tetranucleate sac; 1210. 
Fic. 8.—Division of the four nuclei; 1210. 
Fic. 9.—Ovule showing an 8-nucleate sac; X 1210, 
Fic. 10.—Polar nuclei fusing; x r210. 
Fic, 11.—Mature embryo sac, just before fertilization; 1210. 
Fic. 12.—Fertilization; 1210. 
Fics. 13-17.—Abnormal ovule with two embryo sacs; X 1210. 
Fic. 18.—Section through this ovule not showing the embryo; X 520. 
Fic. t9.—After the first divisions of the primary endosperm nucleus; 
Fic. 20.—Later stage in endosperm formation; X 1210. 
Fic. 21.—Part of an ovule showing the young chalazal haustorium; X 520. 
PLATE IX 
Fic. 22.—Older chalazal haustorium; 52 
Fic. 23.—Proembryo imbedded in saa the chalazal haustorium 
cannot be seen in this section; X 26c. 
Fics. 24—27.—Stages in the development of the embryo; figs. 24, 25, 27, 
X210; fig. 26, 575. 
IG. 28 URaabeve from the mature seed; 
Fic. 29.—Surface view of the testa of the Se ae: X 605. 
