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AMERICAN JOURNAL OF BOTANY 
[VoL io, 
Fig. 12. Chromosome from the same cell as those shown in figures i, 2, and 7. 
Fig. 13. Chromosomes in diakinesis. 
Plate XXX 
The photographs were taken with a Zeiss apparatus, 2 mm. apochromatic objective, 
N.A. 1.4, compensation ocular no. 4, bellows 50 cm. Arc and color screens. X 1500. 
Fig. 14. Metaphase (somatic) in the staminate hair of Tradescantia stained by aceto- 
carmine 1 : 4. The chromomeres are quite distinguishable. 
Fig. 15. The same stage in a staminate hair suspended in 3 percent cane sugar. 
Living chromosomes. 
Fig. 16. An eight-hour preparation of metaphase pollen mother cells stained by 1 : 1 
aceto-carmine. The chromomeres are especially clear. Tradescantia virginica. 
Fig. 17. Similar to figure 16, but showing the hollow construction of the upper chromo¬ 
some as well as the spiral arrangement of the chromomeres in the linin matrix. Tradescantia 
virginica. 
Fig. 18. Metaphase pollen mother cells of Rhoeo suspended in 1 : 1 aceto-carmine. 
Compare the serial order of the chromomeres with those of figure 17 and figure 16. 
Fig. 19. Anaphase figure in the staminate hair of Tradescantia. Living chromo¬ 
somes, intended to show the hollow chromosome structure in the two end views in the 
upper half of the division figure. Suspended in 3 percent cane sugar. 
