EVOLUTION OF THE HUMAN SPECIES 181 



although dwarfs only fifteen inches high have been 

 known, while " giants " sometimes occur with a height 

 of nine feet and five inches. Such individuals are of 

 course rare and abnormal, and are not to be taken 

 into account in establishing the average stature of 

 a race for use in comparison with that of another 

 group. 



The color of the skin is another criterion of racial 

 relationship, though it is more variable in races of com- 

 mon descent than we are wont to assume. We are 

 familiar with the fair and florid skin of the northern 

 European, the fair and pale skin in middle and southern 

 Europe, the coppery red of the American Indian, the 

 brown of the Malay, of the Polynesian and of the Moor, 

 the yellowish cast of the Chinese and Japanese, and 

 the deeper velvety black of the Zulu ; but it has been 

 found that many of the close relatives of the black are 

 lighter in skin color than some of our Caucasian rela- 

 tives, so that this character cannot be taken by itself 

 as a single criterion of racial affinity. 



Perhaps the most conservative and most reliable 

 character that serves for the broad classification of the 

 human races is the shape of the individual hairs of the 

 head. We are familiar with the straight lank hair of 

 the Mongolian peoples and of the various tribes of 

 American Indians, in whom the hair possesses these 

 peculiarities because each element grows as a nearly 

 perfect cylinder from the cells of the skin at the bottom 

 of a tiny pit or hair-follicle. The familiar wavy hair 

 of white men owes its character to the fact that the 

 individual elements are formed by the skin, not as pencil- 

 like rods, but as flattened cylinders. They are oval or 



