Fig. 3. Behaviours elicited in control animals by touching three locations on the body. (A) Distribution of behaviours elicited by touching the anterior, the midbody or the posterior of the leech (N=22). The most common response varied with touch location: shortening at the anterior, local bending in the midbody, and crawling at the posterior. (B) Distribution of behaviours along the CCA1 behaviour score axis. (C) Distribution of individual CCA1 scores. The distribution of behavioural responses elicited by touch at the anterior are farthest from the distribution of behaviours elicited by touch at the posterior; the distribution of responses to midbody stimulation lies between the other two. See Table 1 for a description of the behaviours.