definite to outline a considerable part of the
course of luunan development.
The object matter of American archteolog^' comprises ( 1 ) human remains imbedded in natural deposits or entombed in prehistoric structures, and (2) artifacts in wide variety, including (a) habitations, (b) mounds and other structures connected with habitations or places of worship, (c) gaminj; devices, (d) tools, implements, and weapons, (e) ceremonial ob- jects, (f) domestic and ceremonial utensils, (g) shrines and monuments, (h) petroglyphs, (i) moldings in stucco, (j) sculptures, (k) mis- cellaneous inscriptions. (1) wrought metal ob- jects, etc. The various artifacts may be grouped under a few general designations based on pre- vailing types siich as earthworks, stone imple- ments, pottery, etc.
Human Remain.?. Bones of prehistoric men are exceedingly common in the mounds and other burial places of central and eastern United States; skeletons, with and without integument. have been found in caves throughout nearly all of both Americas, and are fairly common in the arid districts: and complete mununics of pre- historic bodies, with complete wrappings, have been found in large numbers, especially in Peru. The chief lesson taught by these remains is that the prehistoric inhabitants of the various dis- tricts (so far back as this record runs) cor- responded more or less closel.y, in most cases exactly, with the tribes found there by Caucasian explorers, the correspcindence extending to the mode of burial, the preparation of the body, and the mortuary sacrifices, as well as to the somatic or physical characteristics of the individuals. In some cases diversities between the living and the dead have been found of such sort as to indicate migrations or displacements of tribes, and in a few instances these have thrown useful light on early movements of the aborigines; but in a gen- eral view, these indications are of minor impor- tance. By some students, numbers of prehistoric crania have been grou|)C(l by types — e.g. dolicho- cephalic and brachycephalic — assumed to repre- sent distinct genetic stocks or races; but since the ty])es merge in very large series, since both are sometimes found in the same mound or ceme- tery (and even in the same living clan) . the value of the cranial classification would seem hut secon- dary at the best. In some instances the prehis- toric skeletons, especially the crania, throw light on customs; thus the iluniz collection of 10011 Peruvian crania, of which 10 were trephined in 24 distinct operations, proves that the pre- historic folk of this region performed this critical operation with a frequency higher even than that of a modern militarv hos- pital, and with a degree of success hardly exceeded by that of the best modern surgery. Similarly the di-^tribution of deformed crania throws light on cradle customs and on the half- intentional fiatteniui; of infantile heads in pre- historic times; while the pathologic conditions occasionally revealed by the buried bones serve to exteryl our knowledge of certain diseases and wounds, and of the medical practice of the early tribes.
In a few instances human bones have been found in such associations as to suggest the high geologic antiquity of man in America. The best- known instance is that of the Calaveras skull alleged to have been found in auriferous gravels beneath lava beds near Angels, Cal, ; and its in- terest was enhanced Ijy frequent reports of the finding of stone implements (pestles, mortars, spear-heads, etc.) in gravels of a corresponding age. At the time the associations were reported, the gravels were supposed to be Pleistocene or Quaternary, and the lava still newer, so that the accounts had an air of credibility. During 18S0-95, several geologists resurveyed the region, and ascertained that the auriferous gravels, and even the overlying lava-beds, are of Tertiary (probably early Tertiary) age, so that the alleged associations would seem unworthy of considera- tion unless supported by the strongest possible direct evidence. In 1897 the region was re- examined critically by Holmes and McGee, who discovered (1) that all the alleged occurrences of human relics in the gravel reported during recent years may be ascribed to a natural mis- aj)prehension on the part of workmen and others (the objects falling from the surface into the gravel stratum, to mix with the pebbles in the sluice boxes) ; (2) that most of the mortars and pestles alleged to have been found in the gravels were manufactured from the volcanic rock over- lying the gravel beds ; ( .3 ) that the obsidian blades reported from the gravels are made from material of much newer formations ; (4) that the Calaveras skull is of a type corresponding pre- cisely with that of Indians still living in the same vicinity; (5) that its state of preservation cor- responds closely with that of modern bones after a few .vears' burial in the limestone caverns or calcareous earths of the region: and (fi) that the contemporary testimony concerning the finding of the cranium is contradictory, with the burden against the original allegation. Other reports of the occurrence of human remains in geologic de])osits have come from Trenton ; the first case was that of a supposed Eskimo cranium, al- leged to have been found in Pleistocene deposits, but which was afterward examined by Russell and found to be of modern Algonquian type; another was a human fenuir reported from the same deposits, which is yet imdcr discussion. On the whole it may be said that while the pre- historic human remains of America throw much light on ethnic problems, on the habitats and migrations of tribes, on primitive customs, and so on the later chapters in the development of the aborigines, they throw little light on such questions as those relating to the origin and antiquity of mankind.
Earthworks. The most conspicuous prehis- toric works of America arc mounils and other elevations of earth, such as occur abundantly in the Mississippi Valley; perha])s the best-known examples being Cahokia jlound. near East Saint Louis, and the Etowah Mound in northeastern Georgia. The mounds range from barely per- ceptible elevations to two hundred feet in height, from three to four yards to over half a mile in diameter, and from a hundred square feet to several acres in extent : they number tens, if not hundreds, of thousands: and while they arc most abundant in the neighborhood of the jlississippi and its tributaries, they occur in every State and Territory of the United States and in every American country and district thus far ade- quately examined. Many, if not most, of the simple mounds are tumuli or burial places; a considerable part of those examined have been found to contain human skeletons, sometimes in
