When the mutation first arose, the microchaetae were Minute-like, the black spot on the abdomen of males was almost absent and males were sterile. The following phenotypes were seen with very variable penetrance and expressivity; the leg segments, particularly in the 3rd legs, were short, fat and gnarled, wing vein L5 was shortened and the hind margin of the wing was cut away. The leg phenotype varied independently of the wing effects. The venation effect was a precondition of the cut wing effect. In later generations all phenotypes disappeared except for a slight reduction in bristles and sterility.

RK3.