OF THE BUREAU OF ETHNOLOGY. XXV 
In taking up this subject for original investigation, valuable 
published matter was found for comparison with that obtained 
by Colonel Mallery. His opportunities for collecting materials 
from the Indians themselves were abundant, as delegations of 
various tribes are visiting Washington from time to time, by 
which the information obtained during his travels was supple- 
mented. 
Again, the method of investigation by the assistance of a 
number of collaborators is well illustrated in this work, and 
contributions from various sources were made to the materials 
for study. The methods of obtaining these contributions will 
be more fully explained hereafter. One of the papers ap- 
pended to this report was prepared by Colonel Mallery and 
relates to this subject. 
During the continuance of the Survey of the Colorado River, 
and of the Rocky Mountain Region, the Director and _ his 
assistants made large collections of pictographs. When Colonel 
Mallery joined the corps these collections were turned over to 
him for more careful study. From various sources these pic- 
tographs are rapidly accumulating, and now the subject is 
assuming large proportions, and valuable results are expected. 
An interesting relation between gesture speech and picto- 
graphy consists in the discovery that to the delineation of nat- 
ural objects is added the representation of gesture signs 
Materials in America are very abandant, and the prehistoric 
materials may be studied in the light given by the practices 
now found among Indian tribes. 
STUDIES IN CENTRAL AMERICAN PICTURE WRITING, BY PROF. E. 
8. HOLDEN. 
In Central America and Mexico, picture writing had pro- 
gressed to a stage far in advance of anything discovered to the 
northward. Some of the most interesting of these are the 
rock inscriptions of Yucatan, Copan, Palenque, and other ruins 
of Central America. 
Professor Holden has devoted much time to the study of 
