The ball was floated on an air-stream to reduce friction so that the flies' walking movements were translated into rotations of the ball.
(The ball; was floated; L:on an air-stream; to reduce friction so that the flies' walking movements were translated into rotations of the ball) (the flies' walking movements; were translated; into rotations of the ball)
The ball the flies' walking movements
was floated were translated
L:on an air-stream to reduce friction so that the flies' walking movements were translated into rotations of the ball
into rotations of the ball