A study of the Chromosomes in three species of Pseudococcus. 61 
Fig. 5. Same phase as preceding figure. Chromosomes of clumped group showing 
split. 
Fig. 6 and 7. Progressive condensation stages. 
Fig. 8. Same phase as Fig. 7. Chromosomes of loose group showing split. 
Fig. 9. Metaphase plate with chromosomes not yet fully Condensed. 
Fig. 10. Metaphase plate immediately preceding division. 
Fig. 11. Side view of beginning first spermatocyte division, each chromosome 
dividing along the split. 
Fig. 1 2. Shghtly later division phase. 
Fig. 13. Side and polar views of late anaphase. 
Fig. 14. Diffused stage following first spermatocyte division. 
Second spermatocyte. 
Fig. 15. The two groups beginning to separate. Spindle fibres to clumped group 
normal. 
Fig. 16. Anaphase. Spindle fibres beginning to appear in Connection with the 
loose group. 
Fig. 17. Anaphase showing clumped and loose groups approaching final position. 
Fig. 18. Late anaphase, with five chromosomes in each group. 
Fig. 19. Telophase. Ko trace of a cytoplasmic division. 
Fig. 20. Aureole appearing aroimd loose group. 
Fig. 21. Aureole attaining definite outline. Loose chromosomes becoming diffuse. 
Aureole around clumped group just beginning to appear. 
Fig. 22. First trace of nebenkerne. 
Fig. 23. Swelling of chromosomes of both groups. 
Fig. 24. Both groups with fully regained staining capacity after swelling. 
Fig. 25. Initial stage in the growth of the tail of Spermatozoon. 
Fig. 26. Spermatozoa in process of elongation, still intimately connected with 
cytoplasm of mother cell. 
Pseudococcus citri. 
F'irst spermatocyte. 
Fig. 27. Resting phase. 
Fig. 28. Formation of threads. 
Fig. 29. Loops evolved in the formation of chromosomes from dense chromatin. 
Fig. 30. Further condensation. One cell show'ing lack of clumping often met in 
P. citri. 
Fig. 31. Split definitely showing in both groups. 
Fig. 32. Metaphase plate slightly before final condensation. 
Fig. 33a and b. Metaphase plates. Ko clumping in a. 
Fig. 34. Polar and side views of first spermatocyte division. 
Fig. 35. Diffuse stage following first division. 
Second spermatocyte. 
Fig. 36a and b. Anaphases showing clumped groups with normal sets of fibres 
and loose groups connected with irregulär fibres. 
Fig. 37. Late anaphases. No cytoplasmic division. 
Fig. 38. Elongation of spermatozoa. (Taken from a smear, and slightly flattened). 
