tgtt] SMITH—CLINTONIA 217 
9. MopILewskI, J., Zur wee Ws von Euphorbia procera. Ber. 
Deutsch. Bot. Gesells. 2721-26. 
terior seg von eae Onagraceen. Ber. Deutsch. 
Bot. Gosells. 2'7:287-292. 1900. 
11. Pace, L., Fertilization in i porinadion Bor. Gaz. 44:353-374. 1908. 
12. STEPHEN: Ne, ie Pe e embryo sac and embryo of certain Penaeaceae. 
Ann. Botany 23:363-378. 1909 
13. —-——, Recent progress in the study of the embryo sac of the angiosperms. 
New Phytol. 8:377-387. 1909 
. Went, F. A. F. C., The development of the ovule, embryo sac, and egg 
in the Podostemaceae.- Rec. Trav. Bot. Néerl. 5:1-16. 1908. 
10. 
a! 
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EXPLANATION OF PLATE V 
All the figures were drawn with the aid of an Abbé camera lucida on a 
Leitz microscope. For fig. 1, ocular 1 and objective 7 were used; for all 
the others, a 2 mm., 1.30 aper. apochromatic immersion lens with compensa- 
tion ocular 4. The drawings have been reduced one-half in reproduction. 
Fic. 1.—Apex of nucellus with megaspore mother cell. 
Fic. 2.—Megaspore mother cell with nucleus emerging from synapsis. 
Fics. 3, 4.—First mitosis in megaspore mother cell. 
Fics. 5, 6.—Second mitosis in megaspore mother cell. 
Fic. 7.—Megaspore mother cell with four megaspore nuclei, one healthy 
and three degenerate. 
Fics. 8, 0. —Embryo sac showing first — of fertile megaspore nucleus. 
FIG. 10. — apex of an older embryo sac. 
Fic. 11.—Embryo sac of a fully opened wane in this, as in all the others, 
there are no eee 
