OF THE OKRM CELLS OF METAZOA. 



231 



Figs. 4, 5, Lateral views of synapsis stages, only a few of the chromatin elements shown. 



Fig. (i. Nucleus, synapsis, showing two whole bivalent chromosomes. 



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



Figs. 8, i). 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. 18, 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 linin connections. 



Figs. 1(S, 17. Later prophases, only in Fig. 16 are all bivalent chromatin elements shown ; in Fig. 17 the centrosonx 



pairs on the surface of the nucleus. 

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

 Fig. 19. Pole view of the same stage. 



Euehistua tristigmus, Figs. 80-26. 



Fig. 20. Pole view of spermatogonic monaster. 



Figs. 81, 22. Nuclei of first spermatocytes, rest stage. 



Figs. 2;!, 24. Pole views of monaster, first maturation division. 



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



Fig. 20. Second spermatocyte, chromatin elements not definitely arranged in the equator of the spindle. 



Podistis spinoaus, Figs. 27-29. 



Fig. 27. Pole view of spermatogonic monaster. 



Fig. 28. Telophase of first spermatocyte, nucleus. 



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



Mormidea lugeus, Figs. SO 



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



Fig. 81. Pole view of spermatogonic monaster. 



Fig. 33. Nucleus, postsynapsis stage. 



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



Peribahts Unibolaris, Figs. 34-87. 



Fig. 84. Spermatogonic nucleus, rest stage, 



Fig. 85. Pole view of spermatogonic monaster. 



Fig. 3(1. Nucleus of first spermatocyte, rest stage. 



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



Cosmopepla samifex, Figs. 38-41. 



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 chromatin elements 



Fig. 41. Pole view of the same stage. 



Nezara hilaris, Figs. 42-45. 



Figs. 42, 48, Spermatogonic nuclei, commencement of prophase. 

 Fig. 44. Pole view of spermatogonic monaster. 

 Fig. 45. Nucleus of first spermatocyte, early telaphase. 

 A. P. S. — VOL. XX. DT>. 



