1. Abegg, F. A.: Evaluation of polyploid strains derived from curly-topresistant sugar beet varieties. Proc. Amer. Soc. Sugar Beet Techn. 309–320 (1942).
2. D'Amato, F.: Differenziazione istologica per endopoliploidia nelle radici di alcune monocotildonie. Caryologia3, 11–26 (1950).
3. Amin, K. C.: Apreliminary note on interspecific hybridization and use of colchicine in cotton. Current Sci.9, 74–75 (1940).
4. Anderson, E., andK. Sax: A cytological monograph of the American species of Tradescantia. Bot. Gaz.97, 433–476 (1936).
5. Arenkova, D. N.: Polyploid races in millet (Panicum miliaceum L.). C. R. Acad. Sci. URSS N. s.29, 332–335 (1940).