hedliCka] general CONSIDERATIONS 3 



lost gradually those features that interfered with his advance or 

 became useless— progress which is still unfinished. We know these 

 to be the facts, (1) because all organic form is essentially unstable, 

 plastic, reactive to changing influences, and to this law man's com- 

 plex and relatively delicate organism can form no exception; (2) 

 because the best-authenticated skeletal remains of early man show 

 without exception a more cr less close approximation to more primi- 

 tive primate forms; (3) because these older human forms show, in 

 general, more theroid features in proportion to their geologic antiq- 

 uity; and (4) because morphologic differences have occurred in 

 numerous historic groups of mankind within relatively recent times, 

 are very apparent to-day in the various ''races" of man, and are 

 constantly arising in tribes, in lesser groups, in families, and in 

 individuals. 



Evolutionary changes have not progressed and do not progress 

 regularly in mankind as a whole, nor even in any of its divisions. 

 Such changes may be thought of as a slowly-augmenting complex of 

 zigzags, with localized forward leaps, temporary baitings, retrogres- 

 sions, and possibly with even occasional complete cessations. Thus 

 it would not be reasonable to expect that at any given date in the 

 past or present all the branches or members of the human or proto- 

 human family would be of absolutely uniform type. At all periods 

 some individuals, and even groups, were doubtless more advanced 

 than others from the ancestral and nearer the present human type. 

 Nevertheless, the morphologic status of man in each geologic period 

 had, unquestionably, its boundaries, and there is no evidence or 

 probability that two human beings, a geologic period or more apart, 

 could be so closely related in form that their crania or skeletons 

 would show strictly one and the same t}^e. 



The antiquity, therefore, of any human skeletal remains which do 

 not present marked differences from those of modern man may be 

 regarded, on morphologic grounds, as only insignificant geologically, 

 not reaching in time, in all probability, beyond the modern, still 

 unfinished, geologic formations. Should other claims be made in any 

 case, the burden of definite proof would rest heavily on those advanc- 

 ing them. 



Other considerations bearing on this point have been brought forth 

 in the writer's report relating to ancient man in North America,^ 

 which should be read in connection with the present work. The 

 essence of the subject is that the expectation of important form dif- 

 ferences between all human skeletal remains of geologic antiquity and 

 those of the present era is justified; that the differences presented by 



1 Bulletin SS of the Bureau of American Ethnology. 



