Campbell\—The Embryo-sac of Pandanus. 789 
Fig. 13. Two sections of an embryo-sac of P. Artocarpus with twelve (?) chalazal nuclei ; the 
small cell,/, probably belongs to the nucellus. x 300. 
Fig. 14. Embryo-sac of P. Artocarpus , with six(?) chalazal nuclei; b, the micropylar part of 
the same, showing the two sister cells (x) of the embryo-sac. 
Fig. 15. Three sections of an embryo-sac of P. Artocarpus with twelve chalazal nuclei. 
The two micropylar nuclei are shown in a and b. x 300. 
Fig. 16. Two sections of an embryo-sac of P. odoratissimus , L. f., with fourteen chalazal 
nuclei; two of the nuclei may have belonged to the adjoining nucellar tissue, x 300. 
PLATE LX. 
All figures except 17 and 18 refer to Pandanus coronatus. 
Fig. 17. a , cross-section through the apex of the embryo-sac of Pandanus odoratissimus , 
showing the two micropylar nuclei; b , section through the base of the embryo-sac, showing six 
of the fourteen chalazal nuclei, x 300. 
Fig. 18. Tissue of the nucellus near the embryo-sac, showing cells that resemble young secondary 
sacs, x 600. 
Fig. 19. Longitudinal section of an embryo-sac, showing one of the two micropylar nuclei and 
three of the eight chalazal nuclei, x 300. 
Fig. 20. #, base of an embryo-sac with ten nuclei in addition to the large nucleus shown at b. 
x 300. 
Fig. 21. Embryo-sac with two micropylar and twelve chalazal nuclei, x 300. 
Fig. 22. a, embryo-sac, in which there were thirty-two antipodal cells and four micropylar 
nuclei, forming an egg apparatus and polar nucleus, p. n .; b, c , two sections of the egg apparatus 
from the same sac ; a, egg ; sy , synergidae. x 300. 
Fig. 23. a , b, sections of the egg apparatus from a nearly mature embryo-sac; c, the basal part 
of the same sac, showing the lower polar nucleus, p. n ., just separating from the mass of antipodal 
cells, x 300. 
Fig. 24. a , egg apparatus and polar nucleus, p. n ., from a nearly mature embryo-sac ; b , basal 
region of the same. There were about thirty-six antipodals. A single polar nucleus, p. n., was 
separating from the mass of antipodal tissue, x 300. 
Fig. 25. Basal region of an embryo-sac, about the time of fertilization. There were about 
sixty-four antipodal cells, and three polar nuclei, the latter in process of fusion, x 400. 
Fig. 26. Four fusing polar nuclei from a sac that has just been fertilized, x 400. 
Fig. 27. Endosperm nucleus formed by the complete fusion of probably six polar nuclei. 
A second group of fusing nuclei, seven in number, was present in this same sac. x 600. 
Fig. 28. a, the primary endosperm nucleus in process of division, x 600. b, dividing 
endosperm nucleus of about the same age as that shown in Fig. 29, b. 
Fig. 29. a, one of four nuclei, resulting from the division of the primary endosperm nucleus; 
b, c, endosperm nuclei from a more advanced embryo-sac, but before the development of any cell- 
walls in the endosperm ; d, nucleus at the time of the formation of the first cell-walls in the 
endosperm, x 600. 
Fig. 30. a , an embryo-sac in which there was a group of twelve fusion nuclei, e. n.> and 
a second double nucleus, x , as well as a cell (/) resembling an egg-cell, in addition to an egg 
apparatus of four cells, x 95. b, c, x and / of a —more enlarged. 
Fig. 31. Two sections of the egg apparatus of the embryo-sac shown in Fig. 30. There were 
four nuclei, but the synergidae and egg were not clearly defined. A structure (/. t.) resembling 
a pollen-tube could also be seen, but the nature of this was doubtful, x 600. 
Fig. 32. Five of the twelve polar nuclei of the sac shown in Fig. 30. x 600. 
Fig. 33. a, upper part of the nucellus and embryo-sac, showing a one-celled embryo : sy, 
remains of a synergid. x 235. b, the embryo, x 500. 
Fig. 34. Two sections of a two-celled embryo, x 500. sy, remains of the synergidae. x 500. 
