2d. Gesture speech, which, among tribal peoples, never passes beyond the first stages of linguistic growth; and these stages are probably homologous to the earlier stages of oral speech.
3d. Picture writing, in which we again find some of the characteristics of prehistoric speech illustrated.
4th. It may be possible to learn something of the elements of which articulate speech is compounded by studying the inarticulate language of the lower animals.
The traits of gesture speech that seem to illustrate the condition of prehistoric oral language are found in the synthetic character of its signs. The parts of speech are not differentiated, and the sentence is not integrated; and this characteristic is more marked than in that of the lowest oral language yet studied. For this reason the facts of gesture speech constitute an important factor in the philosophy of language. Doubtless, care must be exercised in its use because of the advanced mental condition of the people who thus express their thought, but with due caution it may be advantageously used. In itself, independent of its relations to oral speech, the subject is of great interest.
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 supplemented.
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 appended 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 pictographs are rapidly accumulating, and now the subject is assuming large proportions, and valuable results are expected.
An interesting relation between gesture speech and pictography consists in the discovery that to the delineation of natural objects is added the representation of gesture signs. Materials in America are very abundant, 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. S. HOLDEN.
In Central America and Mexico, picture writing had progressed 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.