Figure 3.

Head movement patterning in quail and caudal brainstem chimeras. (Left) Profiles representing mean head velocities greater than those shown by chickens from 500 ms before crow onset to 1000 ms after crow onset are shown for three different individual quail. Note the general conservation of pattern from individual to individual and the two-part structure consisting of an initial slow phase (given during the first two short notes at the beginning of the crow) and a fast phase (given during the longer amplitude- and frequency-modulated trill at the end of the crow). (Right) Comparison of the morphology of head movement profiles in one chimera of somites 5–7 (Top), one quail (Middle), and one chimera of somites 4–5 (Bottom).