Fig. 8. Kinematics of rapid-start (A,D) and turn-about (B,C) manoeuvres. Resting positions of the larvae are indicated by 0 ms, and the insects are viewed from the side and facing to the right of the page. The dorsal surface of the body is stippled for ease of identification during the following manoeuvres. In each case, the larva receives a light touch to the right side of its head. Details are given in the text. C shows a turn-about manoeuvre in fixed co-ordinates (left). Filled and open circles represent the motion of the fin tip and head, respectively, at 20 ms intervals. The two drawings below and on the right, respectively, show the start and finish positions of the body during a turn-about. Dashed outlines plot the motion of ring vortices released during the extension phase of the manoeuvre and during the final upward tail-flick, respectively. Arrows show the direction of propagation of the ring vortices. (D) Dorsal view of a larva performing a rapid start; , turning angle.