Embryo of Pseudolarix. 647 
Strasburger, E. (’ 84 ';: Neue Untersuchungen liber den Befruchtungsvorgang bei den Phanerogamen 
als Grundlage fiir eine Theorie der Zeugung. Jena, 1884. 
-(’ 92 ) : Ueber das Verhalten des Pollens und die Befruchtungsvorgange bei den 
Gymnospermen. Hist. Beitr., iy, 1892. 
Thomson, R. B. (’ 05 ) : The Megaspore Membrane of the Gymnosperms. University of Toronto 
Studies, Biol. Ser., No. 4, 1905. 
EXPLANATION OF FIGURES IN PLATE XLVIII. 
Illustrating Dr. Miyake and Miss Yasui’s paper on Pseudolarix. 
All figures were drawn with the aid of a camera lucid a. 
Figs. 1-3. Stages in the first division of the microspore, x 1,400. April 2. 
Fig. 4. The first prothallial cell is formed, x 1,400. 
Fig. 5. Division in the formation of the second prothallial cell. Disorganized first prothallial 
cell is seen as a thin deeply staining body, x 1,400. 
Fig. 6. A polar view of a spindle of one of the first two divisions of germinating microspore, 
showing twelve chromosomes, x 1,400. 
Fig. 7. The second prothallial cell is formed, x 1,400. 
Fig. 8. The third division is completed. The generative cell, the tube cell, and the remnants 
of two degenerating prothallial cells are shown, x 1,400. 
Figs. 9, 10. Stages in the division of the generative cell, x 1,400. 
Fig. 11. Mature pollen-grain just before pollination, showing the tube cell, the body and 
stalk cells, besides two degenerating prothallial cells, x 1,400. 
Fig. 12. The two-nucleated stage of the female gametophyte. One of the two nuclei, outline 
of which is shown here, appears in next section, x 480. 
Fig. 13. Young female prothallium surrounded by several layers of tapetal cells. x 90. 
May 22. 
Fig. 14. A lateral basal portion of the periphery of a mature female prothallium, showing the 
structure of the megaspore membrane, x 480. 
Fig. 15. Young archegonium with a single primary neck-cell, x 160. June 6. 
Fig. 16. A later stage with two neck-cells, x 160. June 13. 
Fig. 17. Upper portion of a full-grown central cell shortly before division, x 310. 
Figs. 18, 19. Prophase in the division of the central cell, x 310. 
Fig. 20. Metaphase of the division, x 310. 
Fig. 21. The division is almost completed, x 310. 
Fig. 22. Mature archegonium. x 105. June 26. 
Fig. 23. Cross-section of a mature prothallium showing seven archegonia. x 80. 
Fig. 24. Upper half of a mature egg, showing an extra nucleus (x) just below the disintegrat¬ 
ing ventral canal-cell ( v.c.c .). x 160. 
Fig. 25. The two daughter nuclei resulting from the first division after fertilization. x 105. 
Fig. 26. A later stage, with the four free nuclei of the proembryo, x 105. 
Fig. 27. The four nuclei at the base of the archegonium. Only two of them are shown, x 105. 
Fig. 28. The eight-nuclear stage, showing the formation of walls between the nuclei, x 105. 
Figs. 29, 30. Formation of the proembryo is completed, x 105. 
Fig. 31. A later stage, showing the elongating suspensor. x 105. 
