76 SOCIAL EVOLUTION 



iu the fourth and fifth cohimns of the diagram there is 

 a somewhat corresponding division, only under the more 

 scientific name of the Eolithic period, the Lower Pale- 

 olithic period, the Upper Paleolithic period, and the 

 Neolithic period. Keane associates the Paleolithic, or 

 rough stone age, with the glacial period in Europe, and 

 the Neolithic, or polished stone age, with the period since 

 the ice ages.^^ 



The Upper and Lower Paleolithic periods are different, 

 in that the lower period is characterized by the evolution 

 of the almond-shaped (amygdaloid) implement, which is 

 unknown in the Eolithic period and rare in the Upper 

 Paleolithic loeriod. This is the typical river drift im- 

 plement. The eolithic implements differ from the lower 

 paleoliths in that they are extremely rough, so primitive, 

 indeed, that some archeologists have hesitated to rec- 

 ognize them as the work of man. They are natural 

 flakes, chips, or nodules of flint that bear traces of utiliza- 

 tion and of having been fitted to the hand.^^ 



Returning to the Lower Paleolithic period of our dia- 

 gram, we find that there are "four well defined epochs 

 based on both stratigraphy and the evolution of the al- 

 mond-shaj^ed implement." These are the Strepyan, Chel- 

 lean, and the lower and upper Acheulian.^^ The fact that 

 archeologists and anthropologists have found it necessary 

 to distinguish between different types of implements 

 shows how there was a gradual evolution of this very 

 low and rudimentary culture to higher and higher stages. 

 Each of these different periods extended over thousands 

 of years. In the Chellean epoch, the almond-shaped im- 



32 Keane, op. cit., pp. 54-55. 



33 See figure 24. 



34 See figures 27, 28 and 29. 



