8 BUREAU OF AMERICAN ETHNOLOGY [bull. 52 



It is seen in prehistoric European stations that in order to extract the 

 marrow ancient man often broke the long bones of animals killed, but 

 it does not follow that all similar fragments of bones have a like origin. 

 The bones of dead animals, especially those of large size, often lie 

 exposed for a considerable length of time on the surface of the ground. 

 Animals die at pools where they become mired, or in localities where 

 other animals pass, as can be seen in numberless cases on the prairies, 

 deserts, pampas, and elsewhere. Their bones may be split longi- 

 tudinally by the action of the elements, and are apt to be broken in 

 every possible way by the feet of anmials, by fallmg or rolling stones, 

 or by pressure within the earth, and the fragments may differ in no 

 way from those produced by man breaking long bones to extract the 

 marrow. So far as the writer has been able to learn and so far as he 

 can conceive, there is no safe means of distinguishmg between the 

 fracture effect of a blow by man on bone recent or ancient and that 

 of a stroke on such bone by the hoof of an animal or by impact of 

 falling stones or earth, fragmentation by the teeth of large carnivores, 

 or, in the case of buried skeletal remains, crushing by the weight and 

 movements of the earth. With all this in view, it is difficult to see 

 how fragments of bones of any kind can of themselves ever mate- 

 rially assist in establishing the fact of man's agency, and especially of 

 his presence at the time when the annual whose bones are found 

 split or broken, lived and died. 



Again, the fact is often overlooked that along with fragmentary 

 long bones offered as evidence of man's agency are found fragments 

 of other bones, without medulla and hence without the marrow for 

 which bones are broken. 



As to scratched, striated, incised, or perforated bones, it is suffi- 

 cient to call attention to the fact that a sharp edge or point driven by 

 force of any kind may produce simple effects similar to those due to 

 an implement wielded by the human hand. Only in cases in which 

 there is clear evidence of design may human agency be established. 

 Mere possibihties or probabilities can not be accepted as positive 

 evidence in dealing with the important problem of man's antiquity. 



Many scratches found on bones are doubtless accidental, produced 

 during the excavation, handhng, or transportation of the specimens. 

 As to the striae and incised markings, in order to be accepted as 

 due to human agency, it should be shown conclusively that they can 

 not be attributed to other causes, as, for example, to the teeth of 

 some rodent or carnivore, which sometimes cut as clearly and deeply 

 as would a knife. It is often difficult and frequently impossible to 

 distinguish cuts due to human agency from those due to animal 

 agency. In some cases, however, we may detect the animal agency 

 of the cuts by their lack of purpose (from the human point of view), 

 by their parallel arrangement or similarity of direction (usually 



