Oct., 1923] 
DARLING — CHROMOSOME BEHAVIOR IN ACER 
457 
Figs. 5, 6. Portions of nuclei during early synapsis, the linin threads becoming 
thicker and the chromatin bodies more closely joined in pairs. 
Figs. 7, 8, 9. Stages in synapsis in which the chromatin becomes spread out from 
each pair of chromatin bodies to form the thick chromatin threads. 
Fig. 10. Late synapsis, in which the chromatin bodies lose their identity in forming 
the chromatin threads. 
Fig. 11. A stage in which the threads are becoming loosened from the synaptic knot. 
Fig. 12. A portion of a nucleus in an early post-synapsis stage. 
Plate XXXII 
Fig. 13. A post-synapsis stage, showing the split threads and the split granules on 
the threads. 
Fig. 14. The chromatin threads, usually bent, are beginning to shorten. 
Figs. 15, 16. Diakinesis; some of the threads appear to be folded to form loops, 
some do not. 
Figs. 17, 18. The nuclear membrane disappearing and the chromosomes becoming 
more condensed and clustered about the nucleolus. 
Fig. 19. A portion of a mother cell with spindle fibers becoming attached to chro¬ 
mosomes; some long chromosomes show the side-by-side pairing as a result of the folding 
of the chromatin thread. 
Fig. 20. A portion of a mother cell in late metaphase; some bivalents are separated 
more than others. 
Fig. 21. Early telophase; the chromosomes retaining their individuality. 
Figs. 22 A, 22 B. Resting daughter nuclei of a single cell, showing the thirteen chro¬ 
mosomes in each nucleus. 
Fig. 23. A tetrad or granddaughter nucleus in the resting stage, showing the thirteen 
chromosomes. 
Fig. 24. A polar view of the metaphase stage of a vegetative cell from the flower 
stalk, showing a general paired condition of the chromosomes and a discarded portion of 
the nucleolus. 
Fig. 25. A late prophase stage of a vegetative cell from the flower stalk, showing a 
general pairing of the chromosomes. 
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