1906] CHAMBERLAIN—OVULE OF DIOON 357 
_ Fic. 11. Longitudinal section through integument and adnate portion of 
nucellus: e, epidermis; el, longitudinally elongated cells of stony layer; et, 
transversely elongated cells of stony layer; ej, endosperm jacket; g, endosperm; 
4, isodiametric cells of stony layer; 7b, bundle of inner vascular system; 7/, inner 
fleshy layer of integument; i, inner layer of longitudinally elongated cells ss 
stony layer; », adnate portion of nucellus; 0d, bundle of outer vascular iene 
oj, outer fleshy layer of integument; ~, parenchyma cells of outer fleshy layer; 
5, stony layer; ¢, cells containing tannin. x2 - 
Fic. 12, Section showing endosperm (e), megaspore membrane (m), an 
endosperm jacket (ej). X 350. 
Fic. 13. Cell of endosperm jacket showing one normal nucleus and a free 
spirem of another nucleus. > 350. es ae 
Fic. 14. Longitudinal section through abscission layer; #, cells containing 
tannin, X 112. Poe 
Fic. 15. Section of archegonia early in December, showing endospe: 
somewhat raised over the archegonia. Natural size. 
Fic. 16. Section of archegonia showing beginning of archegonial chamber. 
Natural size, : 
Fic. 17. Section of archegonia just after formation of ventral canal nucleus. 
X5. 
Fic. 17a. The same, natural size. : . 
Fic. 18. Transverse section of megaspore membrane. X900. kk 
Fic. 19. Section of lateral endosperm at a period aie SE ke initia 
are forming at the apex; 280 cells in entire periphery of section. . 
? : : : = 
Fic. 20. Similar section at a later stage, 780 cells in periphery; the two row 
of cells marked a correspond to the single row a of fig. 19. 88. 
; i . K88. 
Fic. 21. Peripheral portion of endosperm at period of germination. X 
Fics. 22-23. Archegonium initials. X88. 
Fic. 24. Archegonium, Dec. 21. X88. 
Fic. 25. Archegonium early in January. X88. 
Fic. 26. Upper portion of archegonium. X88. oes 
Fic. 27. Upper portion of archegonium, March 7. . | os 
Fic. 28. Upper portion of archegonium, May 13, over two months after co 
was picked. x88. Bee : 
Fic. 29. Nucleus of central cell and nucleolus-like bodies in the cytoplasm 
X 350. ; 
: orm 
Fics. 30-32. Stages in the division of the nucleus of the central cell to 
the ventral canal nucleus and egg nucleus. X 350. 
Fic. 33. Ventral canal nucleus. X 350. 4 
e 
Fic. 33a. Upper portion of egg, showing ventral canal nucleus and egg 
nucleus. x29, 
Fic. 34. Ventral canal nucleus and egg nucleus, April. ae 
Fic. 35. Neck, ventral canal nucleus, and egg nucleus. X41. 
