Fig. 3. Twitch force (A) and length (B) of a muscle fibre bundle preparation from
the transverse muscle mass of the tentacle of Loligo pealei. The
recordings of twitch force and length are superimposed after a stimulus at
time zero. The highest force recording was obtained during an isometric
(constant-length) twitch, and the others (a, b, c, d) were obtained during
isotonic twitch with the force clamped to four different levels. The vertical
lines mark the point at which force was measured. The slopes of the dashed
lines on the length recordings give the velocity of shortening, and the
vertical lines are the same times at which force was measured and mark the
centre of the section from which the slopes were measured.
