2 HEREDITY OF SKIN COLOR IN NEGRO-WHITE CROSSES. 



to this lady in this instance, as in so many others. Miss Florence H. 

 Danielson, who had already spent an entire year in field work upon 

 pauper families in rural districts and had been markedly successful 

 in her work, was selected for the study. In her instructions emphasis 

 was laid upon two points: (i) to ascertain as surely as possible the 

 actual parentage; (2) to get a quantitative determination of the skin 

 color for as many as possible of the children, direct ancestors, and 

 immediate collaterals. This resulted in a lot of data that, with few 

 exceptions, give internal evidence of trustworthiness. Data concern- 

 ing a few families in Louisiana were supplied by special studies made 

 by Miss Susan K. Gillean, of New Orleans. 



The color determinations were made in the following manner: 

 Miss Danielson visited the homes of the colored people and obtained 

 all of the genealogical data that could be furnished. Then the sleeve 

 was rolled up to above the elbow and a part of the skin that is usually 

 covered from the sunlight was thus exposed. The arm was placed on 

 the table by a good light and a Bradley color-top was spun close to the 

 arm and the disks adjusted until they matched, when spun, the color 

 of the skin. Various combinations of black (N), red (R), yellow (Y), 

 and white (W) gave a close approximation to the skin color. 



Acknowledgment must be made of the courtesy with which our 

 field worker was everywhere received. The people acquiesced in 

 friendly fashion to the novel request to allow their skin color to be 

 measured; and in some cases leading persons in the community inter- 

 ested themselves in securing an introduction to the homes which 

 furnished the desired combinations of ancestry. Special acknowledg- 

 ment is made of courtesies extended by Prof. E. L. Mark for introduc- 

 tions that were of great service in Bermuda; to Sir Sidney Olivier, 

 governor of Jamaica; to Rev. and Mrs. Reinke, Mr. Frank Cundall, 

 secretary of the Jamaica Institute, and Mr. Fred. Meyer. In the com- 

 pany of Dr. Alfred G. Mayer, whose introductions were of great value, 

 and of Miss Danielson, the writer visited Jamaica, February 16 to 23, 

 1912, to look over the ground and to secure the co-operation of influen- 

 tial persons in our investigation. Assistance was everywhere cordially 

 offered and given. The Trustees of the Carnegie Institution of Wash- 

 ington afforded me the opportunity to make this study at Jamaica. 



C. EVALUATION OF THE DATA. 



Two points in this study deserve critical consideration : First, the 

 value of the determinations by the color-top; second, the value of the 

 alleged relationships in the families. 



The color-top, made by the Milton Bradley Company, Springfield, 

 Massachusetts, is a little device for expressing color quantitatively. 

 Disks of standard black, red, yellow, and white are arranged so that 

 varying proportions of each are exposed as sectors of the whole circle. 



