ratio is increased elongation increases while force is decreased. Squids have been shown to use muscular hydrostat elongation in prey capture and feeding as well. Bending The bending of a muscular hydrostat can occur in two ways, both of which require the use of antagonistic muscles. The unilateral contraction of a longitudinal muscle will produce little or no bending and will serve to increase the diameter of the muscular hydrostat because of the constant volume principle that must be met. To bend the hydrostat structure, the unilateral contraction of longitudinal muscle must be accompanied by contractile activity of transverse, radial, or circular muscles to maintain a constant diameter. Bending of a muscular hydrostat can also occur by the contraction of transverse, radial, or circular muscles which decreases the diameter. Bending is produced by longitudinal muscle activity which maintains a constant length on one side of the structure. The bending of a muscular hydrostat is particularly important in animal tongues. This motion provides the mechanism by which a snake flicks the air with its tongue to sense its surroundings, and it is also responsible for the complexities of human speech. Stiffening The stiffening of a muscular hydrostat is accomplished by the muscle or connective tissue of the hydrostat resisting dimensional changes. Torsion Torsion is the twisting of a muscular hydrostat along its long axis and is produced by a helical or oblique arrangement of musculature which have varying direction. For a counter-clockwise torsion it is necessary for a right-hand helix to contract. Contraction of a left-hand helix causes clockwise torsion. The simultaneous contraction of both right and left-hand helixes results in an increase in resistance to torsional forces. The oblique or helical muscle arrays in the muscular hydrostats are located in the periphery of the structure, wrapping the inner core of musculature, and this peripheral location provides a larger moment through which the torque is applied than a more central location. The effect of helically arranged muscle fibers, which may also contribute to changes in length of a muscular hydrostat, depends on fiber angle—the angle that the helical muscle fibers make with the long axis of the structure. The length of the helical fiber is at a minimum when the fiber angle equals 54°44′ and is at maximum length when the fiber angle approaches 0° and 90°. Summed up, this means that helically arranged muscle fibers with a fiber angle greater