180 Lawson.— Garnet ophytes of Pseudotsuga Douglasii. 
absence of the membrane at, and for a considerable distance back of, the apex of the prothallium. 
June 3. 
Fig. 18. A longitudinal section of a young archegonium, showing the central cell, two neck- 
cells, and a single layer of jacket-cells. May 17. 
Fig. 19. The same at a later stage, showing the frothy appearance of the cytoplasm of the central 
cell. May 20. 
Fig. 20. The same at a still later stage, showing the central nucleus in the region of the neck 
and preparing for division. May 23. 
Fig. 21. The same at a still later stage, showing the position of the central nucleus at the time 
of spindle-formation. June 3. 
Fig. 22. The nucleus of the central cell undergoing division. June 3. 
Fig. 23. A later stage of the same. The central-canal nucleus is completely separated from the 
egg-cell by a distinct cell membrane. June 3. 
Fig. 24. A later stage of the same, showing the degeneration of the ventral canal nucleus and 
a great increase in the size of the egg-nucleus. June 3. 
Fig. 25. The same at a still later stage. The ventral canal nucleus has become fragmented, and 
the egg-nucleus has continued to increase in size, and has begun to move back towards the centre of 
the archegonium. The spindle fibrils stretching between the two cells are still visible. June 3. 
Fig. 26. The egg-nucleus has reached an enormous size, and occupies a position near the 
central region of the archegonium. Its movement from its original position near the ventral canal 
cell is clearly indicated by the structure and drawn-out appearance of the cytoplasm in the forward 
half of the egg. June 3. 
Fig. 27. A cross-section near the apex of a mature prothallium, showing four archegonia. Each 
archegonium is enveloped by a complete single layer of jacket-cells, and each is separated from its 
neighbour by sterile tissue. May 10. 
Fig. 28. A longitudinal section through the apex of a mature prothallium, showing the 
appearance of the archegonia just before fertilization. June 3. 
Fig. 29. A longitudinal section of the egg-nucleus at a stage soon after the organization of the 
ventral canal cell. The egg-nucleus has attained a considerable size. Very close to the nucleus 
membrane there is an accumulation of several masses of very dense cytoplasm. June 3. 
Fig. 30. A later stage of the same, showing the egg-nucleus more than twice the size of that 
shown in Fig. 29. The dense masses of cytoplasm are larger and more numerous. June 3. 
Fig. 31. The same, showing how much more numerous the dense masses of cytoplasm appear in 
cross-section. By the distending of the nuclear membrane outward between the dense masses of 
cytoplasm, the latter resemble small pockets projecting towards the interior of the nucleus. June 3. 
Fig. 32. A longitudinal section of the egg-nucleus showing the segregation of the chromatin 
from the other nuclear substances. June 3. 
Fig* 33* The same at a later stage, showing a rupture in the nuclear membrane, caused very 
probably by the entrance of the male nucleus. The first sporophyte spindle is being organized 
within the membrane of the egg-nucleus. June 3. 
Fig. 34. A longitudinal section of an archegonium, showing the position of the first spindle 
after fertilization. The nuclear membrane has completely disappeared. June 9. 
Fig. 35. A more highly magnified view of the spindle shown in Fig. 34. The chromatin-like 
granules discarded from the egg-cell become associated with kinoplasmic threads as if a second 
spindle were in process of formation. 
Fig. 36. A longitudinal section of the upper half of an archegonium, showing the vacuolated 
appearance of the cytoplasm caused by the discharge of the contents of the pollen-tubes into the egg. 
Two distinct male nuclei of unequal size are to be seen accompanied by a much smaller nucleus 
which is probably the tube-nucleus. June 3. 
Fig. 37. A longitudinal section of an archegonium, showing the first two free nuclei of the pro- 
embryo. June 3. 
Fig. 38. Four free nuclei of the pro-embryo have passed to the base of the archegonium. 
Fig. 39. Another view of the same. 
Fig. 40. A later stage of the pro-embryo, showing the formation of walls between the nuclei. 
Fig. 41. A view of the embryo proper with suspensors. 
Fig. 42. Another view of the same, showing the suspensor plug. 
