422 MISS M. BENSON—CONTRIBUTIONS ТО THE 
contiguous tier—apparently marked out as an embryo-sac; v., vacuole. Тһе strands can 
be seen here to continue to the base of the nucellus although the section is not exactly 
median throughout. 
Fig. 9. Ditto, gathered Мау 28. Shows development of embryo-sacs in #20 contiguous strands. 
The more advanced one (above) is nearly ready for fertilization. Тһе antipodals have 
become detached by the razor from the upper part, which contains still the synergidze and 
polar unclei. ep., epidermal cap now thirteen cells deep; ¢., tapetum; e.s, e.s., embryo- 
sacs; а., antipodals; f., polar nuclei; p., pedicel. 
Fig. 10. Portion of the sporogenous tissue of nucellus as it appears in longitudinal section. Zc., long 
cell being crowded out. | 
Fig. 11. This drawing is taken from a thick section cut in the fresh material It shows a superficial 
view of apical region of epidermal cap, the cells of which are turgid; between these plunge 
three pollen-tubes (p.£.). m., micropyle; r.ep., receptive cell; n., nucellus ; int., integu- 
ment. 
РглтЕ LXVIII. 
Fagus. 
Fig. 12. Longitudinal section of upper part of nucellus showing pollen-tube (ро...) tunnelling epidermis 
(ер.). $., synergide ; e.c., naked egg-cell. 
Fig. 13. Portion of longitudinal section of nucellus showing embryo-sac with extruded cecum. а., anti- 
podals ; d.n., definitive nucleus ; b.c., base of caecum ; s., strand down which it has made it 
Way ; e.s., main portion of embryo-sac. 
Castanea. 
Fig. 14. Longitudinal median section of nucellus, dated July 8, 1892. a.r., axile row already becoming 
marked out from contiguous strands. 
Fig. 15. Ditto, eleven days later. t., tapetal cell; m.s., mother-cell of embryo-sac. 
Fig. 16. Ditto, July 25. £., tapetal cell; s., pointed cell. 
Fig. 17. This section belongs to an ovule which had ceased to develop normally. Тһе tapetal cells (/.) 
had degenerated and the appearance of the contents of the embryo-sac (e.s.) is not normal. 
b.c., basal cells of axile row ; b.s., spindle-shaped cell. 
Fig. 18. Longitudinal section showing base of axile row, also from an aborting ovule. 2ғ., mother-cell 
of tracheide; b.c., bi-nucleate cells of axile row below the embryo-sac. 
Fig. 19. Upper part of axile row. m., micropyle; e.i., epidermis of inner integument; ¢., tapetum ; 
n.e.c., naked egg-cell ; a., antipodals. 
Fig. 20. Longitudinal section of upper part of nucellus, August 22. m., micropyle; i.i., inner integu- 
ment; e.s., embryo-sac ; d.n., definitive nucleus; m.s., moniliform strands of protoplasm ; 
се., cecum of embryo-sac ; ag., basal part of axile row; s.c., pointed cells. 
Fig. 21. Ditto. d.n., definitive nucleus; a., antipodals; fr., tracheide ; 5.c., basal cell of axile row. 
Puate LXIX. 
Castanea. 
Figs. 22-27. Longitudinal sections of nucellus to show tracheides (fr.). a., antipodal; d., degenerating 
area; m., micropyle; e.s., embryo-sac; d.n., definitive nucleus, faintly indicated only, as the 
section had been treated with Eau de Javelle. 
Fig. 28. Pollen-tubes as found growing freely in the ovarian cavity and entering micropyle (m.). o.i., 
outer integument ; c., ceca of pollen-tube. 
