300 Lawson . — The Gametophytes and Embryo of the 
Fig. 3. A longitudinal section through the end of a pollen-tube showing the body-cell and 
tube-nucleus. Thuja orientalis. May 27. 
Fig. 4. The contents of the tip of an older pollen-tube showing the body-cell and stalk- and 
tube-nuclei. Thuja orientalis. May 22. 
Fig. 5. A section of one of the male cells just before fertilization. May 27. 
Fig. 6. A section of the body-cell some time before the final division which gives rise to the 
two male cells. Libocedrus decurrens. May 31. 
Fig. 7. Two male cells some time before fertilization. Libocedrus decurrens. June 1. 
Fig. 8. A longitudinal section of a young megasporangium showing two megaspore mother- 
cells. Libocedrus decurrens, March 22. 
Fig. 9. A section of two megaspore mother-cells more highly magnified. Libocedrus decurrens. 
March 23. 
Fig. 10. A section of four megaspores just after the first division of the mother-cells. Libocedrus 
decurrens. March 23. 
Fig. 11. A section showing six of the eight megaspores after the second division. Libocedrus 
decurrens. March 23. 
Fig. 12. A section of a megaspore some time after germination showing numerous free nuclei in 
process of division. Libocedrus decurrens. April 13. 
Fig. 13. A section through the lower half of a young female prothallium showing the large 
central vacuole and parietal layer of cytoplasm in which numerous free nuclei lie embedded* 
Libocedrus decurrens. May 8. 
Fig. 14. A section of the parietal layer of cytoplasm more highly magnified and taken from the 
stage shown in Fig. 13. Libocedrus decurrens. May 8. 
Fig. 15. A longitudinal section of the lower half of a young female prothallium showing the 
inward growth of the primary prothallial cells and the consequent diminution in the size of the central 
vacuole. The nuclei are much more numerous at the periphery of the cells exposed to the fluid of 
the vacuole. Thuja orientalis. May 11. 
Fig. 16. A longitudinal section through an archegonial complex showing the single layer of 
jacket-cells surrounding the whole group. Thuja orientalis. May 30. 
Fig. 17. A longitudinal section of an archegonial complex showing a portion of the archegonial 
chamber above, into which the contents of the pollen-tubes have been discharged. Thuja orientalis. 
May 30. 
Fig. 18. A cross-section of an archegonial complex showing the common jacket surrounding 
twenty-three archegonja. Thuja orientalis. May 22. 
Fig. 19, A longitudinal section of an archegonium showing the central nucleus undergoing 
division. Thuja orientalis. May 30. 
Fig. 20. A longitudinal section of an archegonium showing the position of the ventral canal- 
nucleus and the egg-nucleus. Thuja orientalis. May 30. 
Fig. 21. A more highly magnified section of the spindle which gives rise to the egg-nucleus and 
ventral canal-nucleus. Thuja orientalis. May 30. 
Fig. 22. A section of the spindle which gives rise to the ventral canal-nucleus and egg-nucleus. 
Libocedrus decurrens. June 1. 
Fig. 23. A more highly magnified section showing the ventral canal-nucleus and egg-nucleus 
just after the division of the central cell. Thuja orientalis. May 30. 
Fig. 24. A later stage of the same showing the absence of any trace of a membrane between the 
two nuclei. May 30. 
Fig. 25. A longitudinal section through an archegonial complex just before fertilization. 
Libocedrus decurrens. June 6, 
Fig. 26. An archegonium showing the fusion of the male and female nuclei. Thuja orientalis. 
May 30. 
Fig. 27. A more highly magnified view of a similar stage showing the presence of the male 
cytoplasm above the fusing nuclei, and also the presence of numerous so-called ‘ proteid- vacuoles.’ 
May 30. 
Fig. 28. A section of the male and female nuclei in process of fusion showing their relative size 
and the difference in the structure of their chromatic contents Thuja orientalis. May 30. 
Fig. 29. A later stage of the same showing the increase in size of the male nucleus and the 
similarity in the structure of the chromatic contents of both nuclei. May 30. 
