334 SIGN LANGUAGE AMONG NORTH AMERICAN INDIANS. 
the Anadarko group. The uniformity of the signs of those Arapahos, 
Cheyennes, and Sioux who have been secluded for years at one particu- 
lar reservation, so far as could be done by governmental power, from the 
outer world, was used in argument by a correspondent; but some col- 
lected 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 moditied 
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 gest- 
ures that are found in current use are, in their origin, conventional. 
They are only portions, more or less elaborate, of obvious natural panto- 
mime, and those proving efficient to convey most successfully at any 
time the several ideas became the most widely adopted, liable, however, 
to be superseded by more appropriate conceptions and delineations. The 
skill of any tribe and the copiousness of its signs are proportioned first 
to the necessity for their use, and secondly to the accidental ability of . 
the individuals in it who act as custodians and teachers, so that the 
several tribes at different times vary in their degree of proficiency, and 
therefore both the precise mode of semiotic expression and the amount 
of its general use are always fluctuating. Sign language as a product 
of evolution has been developed rather than invented, and yet it seems 
probable that each of the separate signs, like the several steps that lead 
to any true invention, had a definite origin arising out of some appro- 
priate occasion, and the same sign may in this manner have had many 
independent origins due to identity in the circumstances, or if lost, may 
have been reproduced. 
The process is precisely the same as that observed among deaf-mutes. 
One of those unfortunate persons, living with his speaking relatives, may 
invent signs which the latter are taught to understand, though strangers 
sometimes will not, because they may be by no means the fittest expres- 
sions. Should a dozen or more deaf-mutes, possessed only of such crude 
signs, come together, they will be able at first to communicate only on 
a few common subjects, but the number of those and the general scope 
of expression will be continually enlarged. Each one commences with 
his own conception and his own presentment of it, but the universality 
of the medium used makes it sooner or later understood. This inde- 
pendent development, thus creating diversity, often renders the first in- 
terchange of thought between strangers slow, for the signs must be self- 
interpreting. There can be no natural universal language which is ab- 
solute and arbitrary. When used without convention, as sign language 
