Fig. 1. Bract-cell morphology, distribution and lineage. (A,B) Adult leg showing mechanosensory bristles with the associated bract (black arrows), bract-less chemosensory bristles (arrowhead) and trichomes (red arrows). (C) The wing bracts are restricted to the proximal costa (bar). (D) High magnification of the area labelled in C showing mechanosensory (arrow) and bract-less chemosensory bristles (arrowhead). (E,F) Cell-lineage analysis shows that bracts and bristles are not related by lineage: y⁺ clones in a y^– background. Arrows indicate sets of bracts and bristles with different labelling. In all figures, photos that show legs correspond to tibia or basitarsus, apart from Fig. 4A-C and Fig. 5B,F in which, for better resolution, the femur is shown.