90 WEATHERWAX: GAMETOGENESIS IN ZEA MAys 
17. Sargant, E. Recent work on the results of fertilization in angio- 
sperms. Ann. Bot. 14: 689-712. 1900. 
18. Strasburger, E. Einige Bemerkungen zur Frage nach der “doppel- 
ten Befruchtung” bei den Angiospermen. Bot. Zeit. 58: 293- 
316. 1900. 
19. Trelease, W. Two new terms, cormophytaster and xeniophyte, 
axiomatically fundamental in botany. Proc. Am. Phil. Soc. 55: 
237-242. 1916. 
20. True, R. H. On the development of the caryopsis. Bot. Gaz. 18: 
212-226. pl. 24-26. 18093. 
. de Vilmorin, P. L. A hybrid Froth teosinte and corn. Bull. Soc. 
Bot. France. 54: 39-42. pl. I. 1907 
22. Waller, A, E. Xenia and other influences following fertilization. 
Ohio Jour. Sci. 17: 273-284. 1917. 
23. Weatherwax, P. Morphology of the flowers of Zea Mays. Bull. 
Torrey Club. 43: 127-144. pl. 5,6 +f. 1-4. 1916. 
24. —_———._ The development of the spikelets of Zea Mays. Bull. 
Torrey Club 44: 483-496. pl. 23 + f. I-33. 1917. 
25. Webber, H. J. Xenia, or the immediate effect of pollen in maize. 
U. S. Dept. Agr. Div. Veg. Phys. and Path. Bull. 22. 1900. 
Explanation of plates 6 and 7 
PLATE 6 
All figures X 725 
Fic. 1. The archesporial cell. 
Fic. 2. Megaspore ca and disorganized tapetal cell. 
Fic. 3. Megaspore mother voll in synapsis 
Fic. 4. Heterotypic spindle. 
Fic. 5. Dau pet gum pone from reduction division. 
Fic. 6. aspores, ss, and micropylar ster cell in process of division. 
Tw 
Fic. 7. Sie daughter cell and one megaspo e beginning to disintegrate: 
s, functional megaspore. 
Fic, 8. Functional megaspore absorbing the other three. 
Fics. 9-12. Steps in the germination of the megaspore and organization of the 
embryo sac: ss, synergids; e, egg nucleus; ~~, polar nuclei; a, antipodal cells. 
PLATE 7 
Fic. 13. Embryo sac soon after organization, X 725: ss, synergids (position 
shown by dotted lines); e, egg nucleus; , polar nuclei; a, antipodal tissue. 
Fic. 14. Germinating pollen n grain on stigma hairs, X 200 
Fic. 15. Sperm, X 1750. 
Fic. 16. Pollen tube entering embryo sac, X 385: 0, outer integument; #7, 
inner integument; tf, pollen tube; w, ovary wall; s, sperms; , tube nucleus (probably); 
e, egg nucleus; ?, polar nuclei in contact; a, one synergid; other synergid not shown. 
Fic Sperm nucleus, s, in contact with egg nucleus, X 1500 
Fie: 18, 19. Sperm nuclei, ss, in contact with the fusing polar mack. X 1500. 
