78 PROFESSOR HENFREY ON THE DEVELOPMENT OF THE OVULE 



EXPLANATION OF THE PLATES. 



The figures magnified 50 diameters and upward were drawn by the aid of the camera Itidda. 



Tab. XVII. 



Fig. 1 . Vertical section of the ovary of an unopened bud. 



Fig. 2. Placenta with two nuclei (a a) from the same. 



Fig. 3. Vertical section of the ovary, &c., of a flower just opened. 



Fig. 4. Placenta of the same with two nuclei (a, a) and one embryo-sac (A). 



Fig. 5. Section of an ovary somewhat older. 



Fig. 6. Nucleus (a), embryo-sac (b) with germinal vesicle and pollen-tubes at the apex; from fig. 5. 



septum of the bulb not yet developed. 

 Fig. 7- Point of a nucleus and the embryo-sac (i), with a fully-developed septum in the bulb (c). 

 Fig. 8. Apex and unimpregnated embryo-sac, with terminal coagula {dd) and a nucleus (e). 

 Fig. 9. Another more advanced. 

 Fig. 10. Another with a pollen-tube (/) applied. 



Fig. 11. Another when the nucleus (e) is converted into a cell with a cellulose wall (g). 

 Fig. 12. Part of an impregnated embryo-sac [b) attached to its nucleus (a), with endosperm-cells formed 



in it. 

 Fig. 13. Upper end of another one with the endosperm more developed. 

 Fig. 14. Vertical section of an ovary some time after impregnation. 

 Fig. 15. Upper end of the endosperm of an ovule from fig. 14, with the germinal vesicle (g) undergoing 



division. 

 Fig. 16. A less advanced ovule, with the endosperm considerably developed ; the dotted line runs to the 



point of insertion of the inner bulb (fig. 1?) formed by the septum. 

 Fig. 17- The inner bulb (similar to that in figs. 7 & 12) drawn out from the endosperm of fig. 16 ; a, 



nucleus. 

 Fig. 18. Inner bulb drawn out from another endosperm. 



Tab. XVIII. 



Fig. 19. Apex of a young ovule with the embryo (g) dividing into four cells; i, endosperm cells. 



Fig. 20. Placenta and ovules, one fertile, the other barren, of a more advanced ovary ; the future prolon- 

 gations of the embryo-sacs are seen in the placenta : lettering as before. 



Fig. 21. Posterior prolongations of an embryo-sac partly dissected out. 



Fig. 22. Section of an imperfect fruit. 



Fig. 23. Apex of the ovule of fig. 22, with embryo (g) ; d d. coagula ; k. upper cell of the row formed from 

 the germinal vesicle {suspensor) . 



Fig. 24. Upper point of a more advanced ovule, with the embryo [g). The small figure on the left is a 

 section of the ovary from which it was taken, nat. size. 



Fig. 25. Embryo from fig. 24. 



Fig. 26. Placenta and ovule of a fruit nearly as in fig. 27, the placenta p. already torn away from the 

 receptacle : lettering as before. 



