ANTHROPOMETRY 45 



not all anthropologically equidistant. Thus the Whites and the 

 Yellow-browns (including native Americans) are more closely related, 

 than the Negro or the Negrito is with either one of these two strains, 

 and their mixtures will be correspondingly more difficult to separate. 

 Nevertheless with experience, care and certain tests such a separation 

 may be said to be always possible where the mixture is one half and 

 one half, and nearly always where it is one fourth and three fourths; 

 but when the proportion of the blood of one of the component races 

 is less than one fourth, the identification of the mixed-blood becomes 

 frequently a matter of considerable difficulty and in mixtures other 

 than those of the negro and white may be impossible. The estimate 

 of the exact amount of particular blood in a given mix-breed is always 

 more or less a matter of conjecture. 



The criteria which guide us in diagnosing mixed-bloods, are the 

 physiognomy, the color of the skin, the character of the hair, the color 

 of the eyes and the tinge of the mucous membranes. Features such 

 as the mongolic fold of the upper eyelid, shovel-shaped (deeply con- 

 cave) upper incisors, marked freckles, etc., may be additional helps 

 in individual cases, particularly in mixtures of Whites and Yellow- 

 browns. The color of the skin should be observed on the usually 

 covered parts of the chest. 



Skin Tests for Mixed-Bloods. On the pectoral parts of the chest 

 may also be made certain tests developed by the author which in many 

 instances of doubtful mixtures between Whites and Indians or other 

 Yellow-browns, and between Whites and other colored races, will 

 help us to arrive at a conclusion. They are tests for the blood reaction 

 of the skin. In a full-blood individual of the Yellow-brown or other 

 dark races, if the chest is exposed and the observer makes three or four 

 vertical lines over the pectoral parts by drawing his finger nail over 

 the skin with a certain amount of pressure, there will be little or no 

 visible reaction ; but if there is any mixture with Whites the lines will 

 show as fairly broad red marks, and the flush will be of some du- 

 ration both features being the more marked the more white blood is 

 present in the individual under examination, provided he is in the 

 ordinary state of health. In malarial, anaemic and phthisical subjects, 

 where the condition and supply of blood are much altered, the value 

 of this test does not hold good. 



The exact paternal or maternal parentage may in some cases be deter- 

 minable through heritage of special features; but the need for such 

 identification arises only in special instances. 



