  By a {\bf generalized arc\/} we mean a continuum with exactly two
non-separating points; an {\bf arc} is a metrizable generalized arc. It is well
known that any two arcs are homeomorphic (to the real closed unit interval); we
show that any two generalized arcs are co-elementarily equivalent, and that
co-elementary images of generalized arcs are generalized arcs. We also show
that if $f:X \to Y$ is a function between compact Hausdorff spaces and if $X$
is an arc, then $f$ is a co-elementary map if and only if $Y$ is an arc and $f$
is a monotone continuous surjection.
