Fig. 7. Flexural stiffness EI of the tail in the two lateral directions compared. (A) Representative data for one individual showing the linear changes in tail deflection that result when forces between 0.1x10^-7 and 4.5x10^-7N are applied laterally. The calculations for EI (see Materials and methods) derived from the least-squares slopes suggest that bending stiffness is greater in the concave-right direction than in the concave-left direction for this individual. (B) Summary results for flexural stiffness in both directions for all individuals tested (N=13). Stiffness measured when bending in the concave-left direction was not significantly different from bending in the concave-right direction. The middle line in the box plot represents the median, the top and bottom edges of the box show the first quartile, error bars denote the second quartile and plus signs indicate values outside the second quartile.