NORTH AMERICAN INDIANS 



437 



however small, that does not show some of the cultural traits of all its 

 immediate neighbors. One of the most striking characteristics of cul- 

 ture distribution is the constant intergradation of traits, so that only 

 in exceptional instances can the cultures of even two neighboring groups 

 be considered exactly alike. Nevertheless, certain groups often possess 

 in common highly characteristic traits, whence they are said to be of the 

 same general types. The divisions on the accompanying map mark off 

 the limits within which the respective sets of characteristic traits seem 



NORTH PACIFIC CO. 

 AREA. 



CALIFORN 



AREA. 



MEX££0 & 

 CENTRAL AMERICA^ 



Culture Areas in North America. 



to predominate. Thus, the various tribes of Plains Indians have a num- 

 ber of peculiar traits whose distribution in more or less complete as- 

 sociation is taken as indicating the geographical extent of a type of 

 culture. 



