344 
Saxton. — Contributions to the Life-history of 
Fig. 23. Dividing nucleus in a prothallus cell, x 860. 
Fig. 24. Pollen-grain in the micropyle of the ovule, x 950. 
Fig. 25. Young pollen-tube in the apex of the nucellus. x 200. Aug. 23. 
PLATE XXVI. 
Fig. 26. Transverse section of nucellus showing two pollen-tubes, x 120. 
Fig. 27. Tip of a pollen-tube which is just passing into the prothallus, some time before cell 
formation begins. The megaspore membrane had not been penetrated at this time, and had some- 
what contracted. It therefore does not appear in the figure, x 360. Sept. 12. 
Fig. 28. The tip of the pollen-tube very shortly before the body cell divides. It is now far 
down in the prothallus. x 360. Oct. 4. 
Fig. 29. Transverse section of a pollen-tube and surrounding tissue of the prothallus and 
nucellus, to the outside of the latter, x 200. 
Fig. 30. The contents of a pollen-tube very shortly after the formation of the two male cells. 
The latter are seen to be still enclosed in a delicate mother* cell wall, x 360. Oct. 4. 
Fig. 31. Contents of a mature pollen-tube, just before fertilization, x 360. Oct. 12. 
Fig. 32. Tip of an abnormal pollen-tube, x 360. Oct. 4. 
Fig. 33. Archegonium showing the male and female nuclei in contact. A ventral canal cell is 
shown, which is certainly not a normal feature of the archegonium. x 775. Oct. 9. 
Fig. 34. Archegonium and part of pollen-tube. The male and female nuclei are fusing, and 
the cytoplasm of the functional male cell, together with the second male cell, is left behind in the 
tube, x 205. Oct. 9. 
Fig. 34 a. The fusing nuclei and starch sheath of Fig. 34. x 775. 
Fig. 35. Similar to Fig. 34 a, but showing a distinct difference in size between the two nuclei, 
x 775. Oct. 9. 
Fig. 36. Archegonium showing the first division of the fusion nucleus, x 485. Oct. 9. 
Fig. 36 a. Part of Fig. 36 on a larger scale, x 830. 
PLATE XXVII. 
Fig. 37. A later stage than Fig. 36. The daughter nuclei reorganizing. No cell plate is 
being formed, x 830. Oct. 9. 
Fig. 38. The division of the lower daughter nucleus. A cell plate is being formed between the 
grand-daughter nuclei, x 700. Oct. 12. 
Fig. 39. A later stage, after the wall is complete, x 485. Oct. 12. 
Fig. 40. Stage between Figs. 38 and 39, showing cell-plates practically complete between both 
pairs of grand-daughter nuclei, x 485. Oct. 9. 
Fig. 41. Later stage showing wall formation complete in the proembryo. One of the neck cells 
is still visible, x 485. 
Fig. 42. Section showing some of the later divisions in proembryo cells. The upper cell is one 
of the two upper cells corresponding to those of Figs. 40 and 41. x 485. Oct. 12. 
Figs. 42 a and 42 b. Parts of the dividing nuclei of Fig. 42, drawn on a larger scale, from each 
of the two sections in which they are seen, x 830. 
Fig. 43. A similar section to Fig. 42. x 485. Oct. 12. 
Fig. 44. Mitosis in a mature proembryo cell, cutting off an embryo cell from a suspensor. 
x 485. Oct. 12. 
Fig. 45. A slightly later stage than Fig. 44, showing the formation of a cell plate, x 485. 
Oct. 12. 
Fig. 45 a. Part of Fig. 45 on a larger scale. Sixteen chromosomes may be counted at each 
pole, x 830. 
Fig. 46. Suspensor and embryo cell, shortly after the division is complete, x 485. Oct. 12. 
Fig. 47. A slightly later stage than Fig. 46. The suspensor is just beginning to elongate. 
X 830. Oct. 12. 
Fig. 48. A group of four suspensors and embryo cells, at a later stage. Only the ends of the 
suspensors are shown in the section. One binucleate prothallus cell has been drawn ; the other 
surrounding prothallus cells are not shown, x 360. Oct. 12. 
