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 collected signs of other Cheyennes and Sioux differ, not only from those on the reservation, but among each other.  Therefore the signs used in common by the tribes at the reservation seem to have been modified and to a certain extent unified.

The result of the collation and analysis of the large number of signs collected is that in numerous instances there is an entire discrepancy between the signs made by different bodies of Indians to express the same idea, and that if any of these are regarded as rigidly determinate, or even conventional with a limited range, and used without further devices, they will fail in conveying the desired impression to any one unskilled in gesture as an art, who had not formed the same precise conception or been instructed in the arbitrary motion.  Few of the gestures that are found in current use are, in their origin, conventional.  They are only portions, more or less elaborate, of