338 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIv. 
interpret the series, therefore, as an historical series beginning at the 
opposite end. Since both of these tendencies are active in the human 
mind at the present time, it seems much more likely that both pro- 
cesses have been at work constantly, and that neither the one nor the 
other theory really represents the historical development of decora- 
tive design. 
The assumption of a development from realistic design to con- 
ventional design also omits the consideration of one exceedingly im- 
portant element, namely, the style of convention that prevails in the 
types of art of different areas. If geometrical designs developed 
from realistic motives the world over, it still would remain to be 
proved why a certain style of conventionalism belongs to one art and 
another style to another art; and in order to explain in a satisfactory 
way the different styles of art, we should have to accept these as given 
ut a very early stage during the process of conventionalization of 
realistic designs. 
The attempt to explain the processes of oompenttionalivaattion be the 
theory of the influence of technical motives does not seem to offer an 
entirely adequate solution of this problem. It is true that certain 
very simple designs seem to be due almost entirely to the influence of 
technic upon simple decorative tendencies. This influence, however, 
does not reach so far as to determine in detail the character of design 
in the same kind of material or in the same technic. As an example 
of such differences may be mentioned, for instance, the designs in 
woven checkered mattings from West Africa, where peculiar realis- 
tic figures alternate with geometrical band designs; the designs of 
cedar-bark mattings of the Ojibwa and of those of the North Pacific 
coast, and of designs made in the same technic by the South Ameri- 
can Indians. In all these cases the technical conditions are practi- 
cally the same, but the styles differ vastly. It seems necessary, there- 
fore, to assume in the development of design the existence of tenden- 
cies which are due to causes different from the technic, and unrelated 
to the realistic motives which may be current or may have been 
current. 
I have no theory to offer in regard to the origin of these types of 
convention, which presumably was connected with a whole series 
of activities determining the perception and reproduction of forms; 
but it seems desirable to point out by a number of instances the fixity 
of these conventional forms and the deep influence that they have had 
even in apparently realistic forms. I have pointed out in the discus- 
sion of the designs of the blankets of the Chilkat Indians that a great 
many of the older forms can be reduced to two fundamental types, 
and that, no matter what animal may be represented in the art of the 
weaver, it is almost always reduced to one of these two forms.* In 
4G, T. Emmons, The Chilkat Blanket, Memoirs, Amer. Mus. Nat. Hist., III, 
p. 355. 
