OENOTHERA MUTANTS WITH DIMINUTIVE CHROMOSOMES 525 
REFERENCES CITED 
Gates, R. R. ('08). A study of reduction in Oenothera rtibrinervis. Bot. Gaz., 
46: 1-34. 1908. 
• and Nesta Thomas ('14). A cytological study of Oenothera mut. lata and Oe. 
mut. semilata in relation to mutation. Quar. Journ. Micr. Sci., 59: 523-571. 
1914. 
Geerts, J. M. ('11). Cytologische Untersuchungen einiger Bastarde von Oenothera 
gigas. Bericht, Deutsch. Bot. Ges. 29: 160-166. 191 1. 
Lutz, Anne M. ('12). Triploid mutants in Oenothera. Biol. Centralbl. 32: 385— 
435. 1912. 
MacDougal, D. T., A. M. Vail, G. H. Shull and J. K. Small (05). Mutants and 
hybrids of the Oenotheras. 1905. Carnegie Inst. Wash. Pub. No. 24, 57' 
pages. 
EXPLANATION OF PLATE XXIV. 
All figures were drawn with the aid of a camera lucida, Bausch and Lomb i inch 
ocular and dil immersion, ap. 1.9, Figures drawn from sections of root-tips taken. 
from greenhouse rosettes. Cut 7 jw thick and stained with Heidenhain's iron-alunu 
haematoxylin. Figures i-ii taken from transverse, and 12-13 from longitudinal^ 
sections. 
Fig. I. 0. aberrans, plant No. 3878, C. S. H., 1908. Mutant offspring of" 
0. lata X O. Lamarckiana. Polar view of metaphase group showing 14 chromosomes; 
of the usual size and i very small one, the latter occupying a peripheral position on' 
the equatorial plate. 
Fig. 2. 0. aberrans, plant No. 4605, C. S. H., 1909. Mutant offspring of 0. lata 
X 0. Lamarckiana. Polar view of metaphase group showing 14+^-chromQsomes, 
the small body lying farther in the group than in the preceding fig-ure. 
Fig. 3. 0. aberrans, plant No. 4605, C. S. H., 1909. Polar view of metaphase 
group showing 14+i-chromosomes, the small body occupying a peripheral position: 
on the equatorial plate. 
Fig. 4. O. rubrinervis, plant No. 6082, Amsterdam, 1912. Mutant offspring of 
0. lata X 0. Lamarckiana. Polar view of metaphase group showing 14+^-chromo- 
somes. 
Fig. 5. 0. rubrinervis, plant No. 6082, Amsterdam, 1912. Same as fig. 4. 
The small chromosome ot figs. 4 and 5 occupies a peripheral position on the equatorial 
plate in each case. Note also that the small body of this plant appears to be almost 
round and apparently somewhat broader than the ordinary chromosomes. 
Fig. 6. O. gigas, plant No. 3676, C. S. H., 1908. Offspring of 0. gigas. Nuclear 
prophase stage showing chromosome a with clear area near one end. 
Fig. 7. 0. Lamarckiana, plant No. 970, C. S. H., 1907. Offspring of 0. 
Lamarckiana. Polar view of metaphase group of 14 chromosomes showing a with 
clear area at the middle of the body. 
Fig. 8. 0. Lamarckiana, plant No. 983, C. S. H., 1907. Offspring of 0.. 
Lamarckiana. Polar view of metaphase group of 14 chromosomes showing a with, 
clear area between middle and extremit}' of the body. 
