The Function of the Halteres of Flies (Diptera)
- 1 In agreement with nearly all the older authors, and in disagreement with v. Buddenbrock, the disturbance of flight after removal of the halteres in flies consists of a loss of equilibrium. The effects of the removal of the halteres are almost eliminated by fixing a piece of cotton to the tip of the abdomen. This stabilizes the flight and largely compensates for the loss of equilibrium otherwise incurred.
- 2 v. Buddenbrock's conception of a purely stimulatory function for the halteres cannot be maintained; the loss in irritability and spontaneity produced in flies by removing the halteres is largely a shock effect.
- 3 The halteres vibrate during walking. No explanation for this phenomenon has been so far found.
- 4 In the Drosophila mutant “vestigial” reduction of wings and halteres runs parallel. In the mutant “bithorax” the increase in size of the halteres is accompanied by a complete loss of their function, so that flight of the intact “bithorax” is of the same unbalanced type as of the normal wild Drosophila without halteres.
- 5 Generally in Diptera reduction of wings and halteres runs parallel.
- 6 In co-operation with Dr. J. W. S. Pringle a new theory of the function of the halteres has been advanced which regards the halteres as equilibrium organs functioning by the gyroscopic action of the vibrating haltere on the sense-organs in the base of the haltere.