D-group chromosomes involved in satellite associations were identified by the technique of G-banding. Out of a total of 530 D-group chromosomes, 176 were No. 13s, 176 were No. 14s, and 178 were No. 15s. Each pair of D-group chromosomes appeared to have an equal chance of entering satellite associations (X 2=0.015, df=2, P>0.99).