2 BUREAU OF AMERICAN ETHNOLOGY [bull. 52 



alterations in the bones, great difficulties are encountered in the way of 

 a precise physical and chemical determination of the changes that 

 exist, and especially in the evaluation of their chronologic significance. 



In general, to establish beyond doubt the geologic antiquity of 

 human remains, it should be shown conclusively that the specimen or 

 specimens were found in geologically ancient deposits, whose age is 

 confirmed by the presence of paleontologic remains; and the bones 

 should present evidence of organic as well as inorganic alterations, 

 and show also morphologic characteristics referable to an earlier type. 

 In addition, it is necessary to prove in every case by unexceptional 

 evidence that the human remains were not introduced, either pur- 

 posely or accidontally, in later times into the formation in which 

 discovered. 



It will be plain to every critical reader that the age of a find relating 

 to early man in which the above-mentioned requirements have not 

 been satisfied can not be regarded as definitely settled. To accept 

 any specimen as representative of man of a definite geologic period on 

 evidence less than the sum total of these criteria would be to build 

 with radical defects in the foundation. It will be far more profitable 

 to antlu-opology to wait for discoveries that ^dll fulfill the conditions 

 named than to accept cases, howsoever satisfactory they may seem to 

 some, that leave in the mind of the unprejudiced and experienced 

 observer serious doubt as to the true age of the remains. 



Two of the above-named requisites, namely, the morphologic evi- 

 dence of the bones and their post-burial alterations, call for further 

 consideration. 



On the basis of what is positively known to-day in regard to early 

 man, and with the present scientific views regarding man's evolution, 

 the anthropologist has a right to expect that human bones, particu- 

 larly crania, exceeding a few thousand years in age, and more espe- 

 cially those of geologic antiquity, shall present marked morphologic 

 differences, and that these differences shall point in the direction of 

 more primitive forms. 



Man can not have arisen except from some more theroid form 

 zoologically, and hence also morphologically. No conclusion can be 

 more firmly founded than that man is a product of an extraordinary 

 progressive differentiation from some anthropogenic stock, wliich 

 developed somewhere in the later Tertiary, among the primates. He 

 began, then, as an organism that in brain and in body was less than 

 man, that was anthropoid. From this stage he could not have 

 become at once as he is to-day, though in some stages of his evolution 

 he may have advanced by leaps, or at least more rapidly than in 

 others. He must have developed successively morphologic modifi- 

 cations called for by his advance toward the present man, and have 



