Flight interneurons in the locust and the origin of insect wings.

Interneurons involved in the generation of motor activity for flight in the locust were found in the first three abdominal ganglia as well as in thoracic ganglia. The evidence that sets of homologous flight interneurons occur in abdominal and thoracic ganglia supports theories that insect wings originated from movable appendages which were serially distributed along the thorax and abdomen and which were under central nervous control.