"common" theory. Those of the tribe who are less skilled, but who are
not noticed, might be unable to catch the meaning of signs which have
not been actually taught to them, just as ignorant persons among us
cannot derive any sense from newly-coined words or those strange
to their habitual vocabulary, which, though never before heard,
linguistic scholars would instantly understand and might afterward
adopt.

It is also common experience that when Indians find that a sign which
has become conventional among their tribe is not understood by an
interlocutor, a self-expressive sign is substituted for it, from
which a visitor may form the impression that there are no conventional
signs. It may likewise occur that the self-expressive sign substituted
will be met with by a visitor in several localities, different
Indians, in their ingenuity, taking the best and the same means of
reaching the exotic intelligence.

There is some evidence that where sign language is now found among
Indian tribes it has become more uniform than ever before, simply
because many tribes have for some time past been forced to dwell near
together at peace. A collection was obtained in the spring of 1880, at
Washington, from a united delegation of the Kaiowa, Comanche, Apache,
and Wichita tribes, which was nearly uniform, but the individuals who
gave the signs had actually lived together at or near Anadarko, Indian
Territory, for a considerable time, and the resulting uniformity of
their signs might either be considered as a jargon or as the natural
tendency to a compromise for mutual understanding--the unification so
often observed in oral speech, coming under many circumstances out of
former heterogeneity. The rule is that dialects precede languages and
that out of many dialects comes one language. It may be found that
other individuals of those same tribes who have from any cause
not lived in the union explained may have signs for the same ideas
different from those in the collection above mentioned. This is
probable, because some signs of other representatives of one of the
component bodies--Apache--have actually been reported differing from
those for the same ideas given by the Anadarko group. The uniformity
of the signs of those Arapahos, Cheyennes, and Sioux who have been
secluded for years at one particular reservation, so far as could be
done by governmental power, from the outer world, was used in argument
by a correspondent; but some coll