8. A subterminal knob was found on the long arm of chromosome 9 in 38-1174 (segregating sp₁ and lo). This knob is similar in appearance to the chromosome 4 knob, but examination of crosses with unrelated stocks showed no evidence of a translocation involving chromosomes 9 and 4. The knob is quite close to the end of the chromosome with about 1/5 of the long arm beyond it. Seed of this is available.

F. J. Clark