Campbell.—Studies on the Araceae. 
23 
EXPLANATION OF FIGURES IN PLATES I-III. 
Illustrating Professor Campbell’s paper on the Araceae. 
PLATE I. 
Piate I, Fig. 21, refers to Aglaonema sp., the others to Diejfenbachia seguine, 
Schott. 
Fig. 1. Longitudinal section of a young female flower of Dieffenbachia, showing 
the apex ( x ) of the floral axis ; the carpellary leaves, car., and staminodia, st. x 
about 45. 
Fig. 2. The same, more highly magnified. 
Fig. 3. Median section through the pistil of an older flower; pi. placenta, ov. 
ovule, x about 40. 
Fig. 4. Median section of a young ovule, showing the first integument in 1 ., and 
the primary archesporial cell. Leitz, oc. 1, obj. 7. 
Fig. 5. A somewhat older ovule ; the second integument is beginning to develop, 
and the archesporial cell has divided. 
Fig. 6. Apex of an ovule with the archesporium divided into three cells; the 
upper larger one becomes the embryo-sac. 
Fig. 7. The nucellus of an older ovule ; the embryo-sac has elongated, and the 
nucleus is preparing for division. 
Fig. 8. Embryo-sac with two nuclei. Leitz, oc. 1, obj. 7. 
Fig. 9. Median section of a mature ovule, ma., the embryo-sac; nu., apex of 
nucellus; in 1 ., in 2 ., the integuments. 
Fig. 10. Two longitudinal sections of an embryo-sac after the differentiation of 
the egg-apparatus and antipodal cells. 
Fig. 11. One of the antipodal cells and the endosperm-nucleus of a somewhat 
older sac; the endosperm-nucleus is surrounded by starch-granules. 
Fig. 12. The antipodal cells from a slightly older sac; they have collapsed 
somewhat in the process of embedding. 
Fig. 13. The upper part of the nucellus and embryo-sac from a mature ovule, 
showing the two synergidae. Leitz, oc. 1, obj. 7. 
Fig. 14. The egg from the same embryo-sac ; the small dark body,^., is perhaps 
one of the male nuclei from the pollen-tube. 
Fig. 15. Base of the embryo-sac, showing one of the antipodal cells, together 
with the endosperm-nucleus and the surrounding starch-granules. 
Fig. 16. Median section of a very young synandrium, showing two young pollen- 
sacs, sp. x about 45. 
Fig. 17. A single pollen-sac more highly magnified; the shaded cells represent 
the probable extent of the archesporium. Leitz, oc. 1, obj. 7. 
