FIGURE 14:
(a) A bifurcation diagram of a transcritical bifurcation,
(b)(i) a phase portrait corresponding to and (b)(ii)
a phase portrait corresponding to . The stabilities
of the two equilibrium points interchange for parameter values on either
side of the bifurcation point.
and (b)(ii)
a phase portrait corresponding to 
. The stabilities
of the two equilibrium points interchange for parameter values on either
side of the bifurcation point.