Plate VIII.
Trirhabda virgata (Family Chrysomelidæ).
Fig. 1. Equatorial plate from somatic tissues of a male pupa, 27 large chromosomes, 1 small one.
2. Equatorial plate from an egg follicle, 28 large chromosomes.
3. Equatorial plate of spermatogonium, 27 large chromosomes, 1 small one.
4. First spermatocyte, synizesis stage.
5. First spermatocyte, early spireme stage, showing unequal pair of chromosomes.
6-7. First spermatocyte, later growth stages.
8. First spermatocyte, prophase.
9-12. First spermatocyte, metaphase.
13. First spermatocyte, equatorial plate.
14-15. First spermatocyte, anaphase, showing separation of the elements of the unequal pair (l and s).
16. First spermatocyte, daughter plates.
17. Second spermatocytes, equatorial plates.
18. Second spermatocytes, equatorial plates showing V-shaped chromosomes.
19. Second spermatocyte, early anaphase, the small chromosome in metakinesis.
Trirhabda canadense.
20. Equatorial plate from egg follicle, 30 large chromosomes.
21. Equatorial plate of spermatogonium, 29 large chromosomes, 1 small one.
22. First spermatocyte, growth stage showing the heterochromosome group.
23. Heterochromosome group. p = plasmosome, l = large heterochromosome, s = small heterochromosome.
24-27. First spermatocyte, metaphase.
28. First spermatocyte, equatorial plate.
29. First spermatocyte, equatorial plate, small member of the unequal pair only present.
30. First spermatocyte, daughter plates.
31. Second spermatocytes, equatorial plates.
32-33. Second spermatocytes, prophase.
