OF THE OVULE OF CHRISTISONIA. 583 
Jodrell Laboratory, Royal Gardens, Kew. I have to thank 
Prof. J. B. Farmer, who brought the material from India and 
Ceylon, for continual assistance and the many kind suggestions 
which he has afforded me during my work. 
EXPLANATION OF THE PLATES, 
ar=archesporium ; es=embryo-sac; nc—nucellus ; syn—synergide ; ov= 
ovum; pn— polar nuclei; ant=antipodal cells; est, es?=sister-cells of embryo- 
sac; pt=pollen-tube ; d4— definitive nucleus; emb=embryo; end —endosperm 
£—testa ; d=dermatogen; h=hypophysis; s=suspensor. 
Prate XX. 
Fig. 1. Longitudinal section of a young ovule of Christisonia neilgherrica, 
Gardn., showing the archesporium, X520. 
Fig. 2. The same at a rather later stage. x 520. 
Fig. 3. Longitudinal section of a young ovule of C. subacaulis, Gardn., showing 
a double archesporium. x 520. 
Fig. 4. Enlarged archesporium of C. neilgherrica, Gardn., showing division of 
its nucleus. Xx 520. 
Fig. 5. Archesporium of C. neigherrica, Gardn., showing its division into two 
cells. 520. 
Fig. 6. Archesporium of C. neilgherrica, Gardn., showing its division into four 
cell, x 520. 
Fig. 7. A somewhat later stage of the same, showing the developing embryo- 
sac. Xx 520. 
Fig. 8. Two young embryo-sacs in a single ovule of C. neilgherrica, Gardn., of 
which one is becoming crushed. x 520. 
Figs. 9 & 10. Young embryo-sacs of C. subacaulis, Gardn., before division of the 
primary nucleus. x 520. 
Figs. 11 & 12. The same after division of the primary nucleus. x 520. 
Fig. 13. The same, with the nucleus at one end undergoing division. 520. 
Fig. 14. Mature embryo-sac of C. neilgherrica, Gardn., showing the egg-appa- 
ratus, polar nuclei, and antipodal cells. 520. 
Fig. 15. Mature embryo-sac of C. neilgherrica, Gardn., with two persistent 
sister-cells at the micropylar end. x 520. 
Puarte XXI. 
Figs. 16-18. Upper portion of the embryo-sac of C. neilgherrica, Gardn., before 
development of the embryo. x 520. 
Fig. 19. The same, showing the embryo beginning to grow out; only one of 
the synergide is shown. x 520. 
Figs. 20a & 205. Upper portion of the embryo-sae of C. subacaulis, Gardn., the 
embryo beginning to grow out. X 520. 
