Flow is directed from ‘+’ to ‘’ and then reversed from ‘’ to ‘+’
(Figs. 2a and 3a). First order tubes x and y represent input Boolean
variables. The second order tube z represents an output variable
(Figs. 2a and 3a). If there is a flow of cytoplasm in a tube, the tube
represent state True, if there is no flow state False. In an intact, or
resting, state the gate’s inputs are in state ‘1’, tubes x and y exhibit
flow of cytoplasm and tube z does not exhibit a flow: x = 1, y = 1,
z = 0 (Figs. 2b and 3a). This is because tube z’s diameter, approx.
30 mm, is nearly three times smaller than the diameter of tubes x
and y, approx. 100 mm.
When tube x is touched, as shown in Figs. 2c and 3b, tube x
becomes ‘non-conductive’ and the flow through tube x stops. Subsequently,
the pressure of cytoplasm increases and the cytoplasm