22 Miyake, The developinent ol' the gametophytes etc. 



the original size in reproduction. The photomicrographs are taken with the 

 following oculars and objektives: 



Figs. 106 a, 106 b, 107, 112—114: Zeiß Apochromat 2 mm, Comp. Oc. 4. 



Figs. 108-111: Zeiß Obj. B, Comp. Oc. 4. 



Plate I. 



Fig. 1. Microspore mother-cell. 1330. 



Fig. 2. The same in sinapsis. 'A 1330. 



Fig. 3. Spirem stage. ' 1330. 



Fig. 4. Late spirem stage just before the formation of chromosomes. 

 X 1330. 



Fig. 5. Diakinesis stage. >< 1330. 



Fig. 6. Multipolar spindle. < 1330. 



Figs. 7 — 8. Equatorial plate stage of spindle. >( 1330. 



Fig. 9. The same viewed from pole; twelve bivalent chromosomes are 

 Seen. X 1330. 



Figs. 10 — 11. Spindle in anaphase. < 1330. ' > 



Fig. 12. Telophase. X 1330. 



Fig. 13. Daughter-nuclei formed. X 1330. 



Fig. 14. Spindle of second division in metaphase. ; 1330. 



Figs. 15 — 16. The same in telophase. X 1330. 



Fig. 17. Late telophase. ; ; 1330. 



Fig. 18. Four grand-daughter-nuclei formed. X 1330. 



Fig. 19. Young microspores. X 1330. 



Fig. 20. Microspore much more enlarged. \ 1330. 



Fig. 21. Mature microspore. X 660. 



Figs. 22 — 25. Successive stages in first division of microspore. X 660. 



Fig. 26. Mature pollen-grain, containing generative and tube-cells. 660. 



Fig. 27. Generative cell little after division; stalk-nucleus still attached 

 to the body-cell. X 660. 



Fig. 28. Body-cell, stalk- and tube-nuclei, which are found in young 

 poUen-tube. X 660. 



Fig. 29. Body-cell and one of two nuclei. , 660. 



Fig. 30. A part of young pollen-tube with body-cell and two nuclei_ 

 X 660. 



Fig. 31. Pollen-tube about half way penetrated the nucellar cap, with 

 body-cell and two nuclei X 660. 



Fig. 32. Lower part of pollen-tube which has almost completed the 

 Penetration of nucellus. ) 660. 



Fig. 33. A still later stage. X 660. 



Fig. 34. Fully-formed body-cell with two nuclei. ■; 660. 



Fig. 35. Two sperm-cells; a free nucleus found below them shows sign 

 of degeneration. X 660. 



Plate II. 



Fig. 36. Oblique cross-section of a megaspore mother-cell, in synapsis. 

 X 1330. 



Fig. 37. Longitudinal section of megaspore mother-cell, in spirem stage. 

 X 1330. 



Fig. 38. Nucleus of megaspore mother-cell in diakinesis. X 1330. 



