Fig. 4. Force/velocity relationship for a single tentacle transverse muscle bundle preparation (filled circles) and a single arm transverse muscle bundle preparation (open circles). Force is expressed relative to the isometric force of the preparation (mean of repeat twitches for the tentacle and repeat 100 ms, 50 Hz tetani for the arm). Velocity is expressed in L₀ s^-1, where L₀ is the length of the preparation at which peak isometric force is produced. The lines were fitted to the data using Hill's single hyperbolic function (see text and Table 1, tentacle preparation 6 and arm preparation 6).