208 BUREAU OF AMERICAN ETHNOLOGY [bull. 52 



definite facts. However, as already shown in other sections of this 

 paper, and particularly in the report made by the writer on the human 

 bones of reputed geologic age in North America,^ the state of fossiliza- 

 tion of bones, both as to mineralization and loss of organic constitu- 

 ents, is so dependent on local conditions as to be of little service in 

 determining antiquity. Moreover, as also already discussed, the 

 changes in bones are limited in character and extent by the ph3^sical 

 and chemical agencies present, and are not cumulative beyond a cer- 

 tain stage. Hence, in a bone that has reached the limit of the altera- 

 tions caused by the conditions of its surroundings, time would l)ring 

 but little further alteration, and old as well as relatively recent bones 

 may present quite similar "fossilization." This is observable in 

 numerous instances with fossil bones of mammals from diiferent 

 epochs. 



7. The value of the association of the bones of extinct animals with 

 those of man, as a measure of antiquity is, it is necessary to repeat, 

 frequently overestimated. The vital distinction between inhuma- 

 tion of the dead practiced by man since the earliest times and the 

 natural inclusion of bodies of animals in various sediments is often 

 overlooked by the paleontologist. Men dig graves for their dead 

 regardless of the contents of the soil so long as these contents do not 

 greatly impede their work. In ground rich in remains of extinct 

 animals, it is quite probable that the gravedigger removed them and 

 then left them in the earth above or near the body in the same man- 

 ner as he would tosca, pebbles, or other objects found in the ground. 

 It is also possible that some of the fossil bones incidentally became 

 broken, cut, or otherwise marked and even burnt, either before 

 the burial, or by those who attended to it. The significance of the 

 association of fossil animal bones ^vith human bones, even in the cases 

 in which the former show effects of man's activity, is entirely problem- 

 atic. The enumeration by the paleontologists in this and other 

 cases, of long lists of names of extinct animals found with or near the 

 the human bones, or in the vicinity, or in the same strata, is impres- 

 sive, but alone counts for httle as evidence of the age of the remains 

 of man found in such relation. The scale of the Hoployliorus found 

 with the Arroj^o de Frias human remains proves only the action of 

 fire, not the mode in which it was burned nor the time or cause of 

 the occurrence. 



8. As to perforated, grooved, and broken bones of animals, it should 

 be shown in every case that their condition in these respects is not due 

 to any agency other than man, and that the changes were made 

 when the bones were fresh, in order that the evidenc3 may be em- 

 ployed in determining man's contemporaneity with the animals 

 which the bones represent. This also suggests the fact, which de- 



1 Skeletal Remains, etc., Bulletin 33 of the Bureau of American Ethnology. 



