1. M. J. D. White,Animal Cytology and Evolution, 2nd edn (Cambridge University Press 1954).
2. C. P. Swanson,Cytology and Cytogenetics (Prentice Hall, New Jersey 1957).
3. Sally Hughes-Schrader, J. Morph.70, 261 (1942).
4. Uzi Nur, Chromosoma13, 249 (1962).
5. T. S. Painter, Am. Nat.69, 50 (1934).