12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 83 



Transitional 



Aciliau-Tardctwisian (first after Alas d'Azil, southern France; second after 

 another locality in France; both somewhat indefinite) 



Neolithic or New Polished Stone Age 

 Various local subdivisions ; emerges into historic 



Copper-Bronze Age 

 Early historic 



Iron Age 

 Historic 



The principal forms of the stone implements that characterize these 

 different cultural subdivisions of man's past are shown in many books 

 and other writings on 'prehistory. So far as contributions in English 

 are concerned, and for details and additional materials the reader 

 must be referred to the reliable recent works of MacCurdy/ Burkitt," 

 Miss Boyle/ and Peake with Fleure.^ To a large number of earlier 

 publications references will be found in these authors. 



The true geological relation and the exact antiquity of the older 

 parts of man's prehistory is still, it may be repeated, more or less 

 uncertain, due partly to the far from complete archeological and 

 paleontological knowledge, but even more so to the uncertainties about 

 the exact subdivisions and duration of the Ice Age. The charts shown 

 in figures i, 2, 3, and 4 give approximations of the human and the geo- 

 logical conditions. Such approximations are becoming gradually more 

 and more definite for the period since the greatest intensity of the 

 last glaciation ; for the rest of the Ice Age they can only be provisional. 



One of the foremost needs and wishes of all who deal with man's 

 antiquity is the possibility of estimation of the different subdivisions 

 of this in years. Geological terms alone do not suffice; what is needed 

 is the application to the various periods of human prehistory of 



' MacCurdy, G. G., Human Origins. 2 Vols., New York and London, Apple- 

 ton & Co., 1924. 



* Burkitt, M. C, Prehistory. Cambridge, England, University Press, 1921. 



* Boyle, Mary E., In Search of Our Ancestors. Boston, Little, Brown & Co., 

 1928. 



* Peake, H., and Fleure, H. J., The Corridors of Time. A series of 8 small 

 volumes dealing with human prehistory and later stages. New Haven, Yale 

 University Press, 1927-1929. 



