  We show that the behavior of the excitation curves of some $e^+e^-$
annihilation processes close to the nucleon-antinucleon threshold can be
explained either by the $\rho(1900)$ resonance itself or by its interference
with other resonances. Besides the six-pion annihilation and the $e^+e^- \to
K^+K^-\pi^+\pi^-$ and $e^+e^- \to \Phi \pi^0$ processes, we also analyze the
final states $\eta \pi^+ \pi^-$, $K^+ K^- \pi^+ \pi^- \pi^0$, and $K^+ K^-\pi^0
\pi^0$, the behavior of which around 1.6 GeV has not yet attracted attention.
Analysis of the data on the $e^+e^- \to p \bar p$ and $e^+e^- \to n \bar n$
reactions clearly shows that the $\rho(1900)$ resides above the $n \bar n$
threshold.
