544 Brown: EMBRYO-SAC AND EMBRYO IN PHASEOLUS 
Explanation of plates 25 and 26 
All drawings were made with an Abbé camera lucida at table level. Leitz oculars 
d objectives were used: Fics. 1, 2, 6-10, 14-20, 22, with ocular 4, oil immersion 
objective 1/16, tube length 222 mm. (X 2,475); FIGS. 4, 5, II-13, 21, 23, 25, with 
ocular 4, oil immersion objective 1/16, tube length 170 mm. (X 1,740); Fics. 24, 26, 
28, with ocular 3, oil immersion objective 1/16, tube length 170 mm. (X I, 530); Fic. 
3, with ocular 1, oil immersion objective 1/16, tube length 140 mm. ( X 966); FIG. 27, 
with ocular 3, objective 3, tube length 170 mm. (X 170); Fic. 29, with ocular 3, 
oil immersion objective 1/16, tube length 140 mm. (X 570). The drawings on 
PLATE 25 have been reduced one half in reproduction; those on PLATE 26, two thirds. 
PLATE 25 
Fic. 1. Young nucellus showing enlarged hypodermal cell. 
Fic. 2. Young macrospore mother cell 
Fic. 3. Nucellus showing two macrospore mother cells in an axial row. 
Fic. 4. Nucellus showing the position of the young macrospore mother cell 
represented on a larger scale in Fic. 2 
1G. 5. ucellus showing two eer of cells between the epidermal layer and 
the macrospore mother cell. 
Fic. 6. Fully grown macrospore mother cell. 
IG. 7. Macrospore mother cell with nucleus in synapsis. 
Fic. 8. Ore mother cell with nucleus in division. 
Fic. re melee _— Kee pesinspiie: the oe upper ones are degenerating, the 
third h 
¥ bryo ats rk 
Fic. 10. ‘Mature egg. 
PLATE 26 
Fic. 11. Functional macrospore with the two degenerating macrospores lying 
above it in the n lus 
FIG. hee embryo-sac. 
Fic. 13. : etree cme 
G. 16. Polar nuclei fus 
Fic. 17. An egg and two endosperm nuclei. 
Fic. 18. A two-celled pro-embryo. 
Fic. 19. The second division in the pro-embryo. 
Fic. 20. A three-celled pro-embryo. 
1G. 21. The terminal cell of the phage ty has divided longitudinally. 
Fic. 22. An embryo consisting of s 
Fic. 23. An 2 after further ruse divisions have occurred; the basal 
cells are enlargin: 
FIG, 24. a have showing anticlinal walls in the terminal cells. 
Fic. 25. Periclinal walls in the embryo proper. 
Fic. 26. An older pee showing suspensor with no distinct ancien 
between it and the embry 
roper. 
ide 27. minter= showing See deca hypocotyl, and epicotyl. The basal 
Fic. 15. Egg and cynergids showins filiform apparatus. 
Fic ing. 
Fic. 8. Endospein nuclei dividing. 
Fic. 29. Endosperm cells formed in the region of the embryo. 
