Campbell. — Studies on the Araceae. 
685 
EXPLANATION OF FIGURES IN PLATES 
XXX, XJCXI, AND XXXII. 
Illustrating Professor Campbell’s Studies on the Araceae. 
PLATE XXX. 
All figures refer to Aglaonema commutatum. Figs. 1, 7, 15, Leitz, oc. 3, 
obj. 3. Figs. 12, 13, 14, 16, 17, Leitz, oc. 1, oil imm. 1/1 6 ; the other figures, 
Leitz, oc. 1, obj. 7. 
Fig. 1. Median longitudinal section of young ovule, showing the young embryo- 
sac, m } and the two integuments in lf in 2 . 
Fig. 2. The nucellus and embryo-sac, more highly magnified. 
Fig. 3. Oblique section of the nucellus, showing two young embryo-sacs, 
apparently derived from the division of a common mother-cell. 
Fig. 4 a, b. Two sections of young embryo-sac with two nuclei, c, Nuclei from 
the lateral cells of the nucellus, more enlarged, showing the very much compressed 
form. 
Fig. 5. Section of a nucellus with two young embryo-sacs; each contains four 
nuclei. 
Fig. 6. Embryo-sac containing four nuclei, all at the micropylar end. (Three 
only shown in the section.) 
Fig. 7. Nearly median section of an ovule with three embryo-sacs. 
Fig. 8. The details of the sacs shown in Fig. 7, more highly magnified, a f 
contains a single nucleus ; b, eight nuclei in two groups, partially fustd ; c d , and 
e, the details of sac c : d, antipodals (?), 0, egg (?), c , fusing endosperm nuclei. 
Fig. 9. Sections of embryo-sac with four nuclei, three at the micropylar end, a 
single one, b, at the chalazal end. 
Fig. 10. Sections of a sac with eight nuclei, in two groups of four ; no definite 
polar nuclei recognizable. 
Fig. 11. Two sections of an ovule with three large cells (embryo-sacs?), but 
probably abnormal. The largest of the three cells contained but two nuclei (r). 
What looked like a pollen-tube,/, t ., occupied the micropyle, above the apex of 
the nucellus. 
Fig. 12 a. Upper part of nucellus, showing the pollen-tube, p. t. The cell 
with the two nuclei probably represents a second, imperfect embryo-sac. The 
lower embryo-sac contained twelve nuclei, in three groups, b, the four antipodal 
nuclei, c, four nuclei fusing, presumably to form the endosperm-nucleus. 
Fig. 13. Two sections of the apex of a sac, with what seemed to be a very broad 
pollen -tube, p. containing a generative nucleus, g. There were four cells 
at the apex, of which two hemispherical ones, 0, o ' , were much alike. One of 
these is probably the egg-cell. 
Fig. 14. Nuclei from the cavity of the embryo-sac shown in Fig. 13. There 
were four nuclei, two in process of fusion, and two (only one shown in the section) 
which were apparently disintegrating. No antipodal cells were present. 
Fig. 15. Section of a group of three embryo-sacs ; the two upper ones degeneia- 
