OF THE GEEM CELLS OF METAZOA. 231 



Pigs. 4, 5. Lateral views of synapsis stages, only a few of the cbromatin elements shown. 



Fig. 6. Nucleus, synapsis, showing two whole bivalent chromosomes. 



Fig. 7. One whole bivalent chromosome, end of the synapsis stage. 



Figs. 8, 9. Postsynapsis stages, in each three whole bivalent chromosomes shown. 



Fig. 10. Telophase of the spermatocyte, showing two whole bivalent chromosomes. 



Fig. 11. Late telophase, showing eight bivalent chromosomes. 



Fig. 12. Rest stage of spermatocyte. 



Figs. 13, 14. Early prophases of first maturation division, each figure showing two whole bivalent chromosomes. 



Fig. 15. Two whole bivalent chromosomes, a little later stage than the preceding, showing their liuin connections. 



Figs. 10, 17. Later prophases, only in Fig. 16 are all bivalent chromatiu elements shown ; in Fig. 17 the eentrosomc 



pairs on the surface of the nucleus. 



Fig. 18. Lateral view of the monaster of the first maturation mitosis, all chromatin elements shown. 

 Fig. 19. Pole view of the same stage. 



Suchistus tristigmus, Figs. 20-2G. 



Fig. 30. Pole view of spermatogonic monaster. 



Figs. 21, 22. Nuclei of first spermatocytes, rest stage. 



Figs. 23, 24. Pole views of monaster, first maturation division. 



Fig. 25. Lateral view of spindle, first maturation division (showing all chromatin elements). 



Fig. 26. Second spermatocyte, chromatin elements not definitely arranged in the equator of the spindle. 



Podisus spinosus, Figs. S7-S9. 



Fig. 27. Pole view of spermatogonic mouaster. 



Fig. 28. Telophase of first spermatocyte, nucleus. 



Fig. 29. Pole view of monaster, first maturation mitosis. 



Mormidea lugens, figs. 30-33. 



Fig. 30. Nucleus of spermatogonium, commencement of prophasc. 



Fig. 81. Pole view of spermatogonic monaster. 



Fig. 32. Nucleus, postsynapsis stage. 



Fig. 33. Pole view of monaster, first maturation mitosis. 



Peribalus limbolaris, Figs. 34-37. 



Fig. 34. Spermatogonic nucleus, rest stage. 



Fig. 35. Pole view of spermatogonic monaster. 



Fig. 36. Nucleus of first spermatocyte, rest stage. 



Fig. 37. Pole view of monaster, first maturation mitosis. 



Cosmopepla carnifex, Figs. 88-41. 



Fig. 38. Pole view of spermatogonic monaster. 



Fig. 39. Nucleus of first spermatocyte, rest stage. 



Fig. 40. Lateral view of the spindle, first maturation mitosis, showing all chromatiu elements. 



Fig. 41. Pole view of the same stage. 



Nezara hilaris, Figs. 42-45. 



Figs. 42, 43. Spermatogonic nuclei, commencement of prophase. 



Fig. 44. Pole view of spermatogonic monaster. 



Fig. 46. Nucleus of first spermatocyte, early telaphase. 



