Peripheral and central nervous system projections in normal and mutant (bithorax) Drosophila melanogaster.

Projections of axons from the wing, haltere and the head are described from silver intensified cobalt preparations of normal and bithorax mutant Drosophila. Dorsal projections from the homeotic wing into thoracic ganglia and to the brain are haltere-like. Ventral projections are wing-like. In general these results are in complete agreement with previous studies by Palka et al. and Ghysen. However, considerable variation of projection patterns is seen between individual mutant animals some of which were previously described only from mosaics (clones off bithorax sensory fibers into normal ganglia). Evidence for possible transformations of the third thoracic ganglion in mutants is therefore ambiguous.