178 ANNALS NEW YORK ACADEMY OF SCIENCES 



size of the face. Thus types like the Europeans, the Ainu of Japan and 

 some Indian tribes of the Pacific coast exhibit certain striking similari- 

 ties in form. This tendency to parallel modification of the type indi- 

 cates early relationship. 



After these conditions had developed, one of the last ice ages set in. 

 The members of the race that lived in America were cut off from their 

 congeners in the Old World, and during a long period of isolation an 

 independent development of types occurred. Still the time was not long 

 enough to wipe out the family resemblance between the Asiatics and 

 Americans, which persists up to this day; but numerous new lines of 

 growth developed. The face assumed a distinct form, principally through 

 the increase of size of the nose and of the cheek-bones. The wide spread 

 of the race over the whole territory of the two Americas that was free 

 of ice, and the isolation and small number of individuals in each com- 

 munity, gave rise to long-continued inbreeding, and, with it, to a sharp 

 individualization of local types. This was emphasized by the subtle influ- 

 ences of natural and social environment. With the slow increase in 

 numbers, these types came into contact; and through mixture and migra- 

 tion a new distribution of typical forms developed. Thus the American 

 race came to represent the picture of a rather irregular distribution of 

 distinct types and colors, spread over the whole continent. The color of 

 the skin varied from light to almost chocolate brown; the form of the 

 head, from rounded to elongated; the form of the face, from very wide 

 to rather narrow; the color of the hair, from black to dark brown and 

 even blond, its form from straight to wavy; the lips were on the whole 

 moderately full; the nose varied from the eagle nose of the Mississippi 

 Indian to the concave nose of some South Americans and northwest 

 Americans. Notwithstanding the wider distribution of these types, each 

 area presented a fairly homogeneous picture. 



Gradually the great ice-cap retired. Communication between America 

 and Asia became possible, while Europe was cut off by the wide expanse 

 of the Atlantic Ocean. Man followed the ice-cap northward. Members 

 of the American race crossed over to Asiatic soil and occupied parts of 

 Siberia, where finally they came into contact with the Asiatic group, 

 which had also spread northward with the retreat of the ice. 



Even at this early time, when the tribes were small in number and 

 weak, human migration was only halted by impassable barriers ; and thus 

 contact of members of one group with those of another was not rare, and 

 was always accompanied by the exchange of inventions and other cultural 

 possessions. 



We must revert once more to the earlier period, when man first entered 



