1. Aase, H. C.: Cytology ofTriticum, Secale andAegilops hybrids with reference to phylogeny. Res. Stud. State Coll. Wash.2, 5–60 (1930).
2. Armstrong, J. M. undR. W. Robertson: Studies of colchicine induced tetraploids ofTrifolium hybridum L. I. Cross and selffertility and cytological observations. Canad. J. agr. Sci.36, 255–266 (1956).
3. Camara, A.: Ann. Inst. Sup. Agron., Lisboa7, 29–61 (1935); zitiert nachSears (1948).
4. Cua, L. D.: Zitiert nach Wis Nr.1 (1954), (1949).
5. Darlington, C. D.: Recent advances in cytology. 2. Aufl. London 1937.