5 TRANSACTIONS OF THE 



sex, giving the percentage found in over 1,200 examinations 

 as 0.26 per cent, among females. He attributed this low 

 percentage, as compared with the male sex, to the greater 

 development of the color-sense in women on account of their 

 occupations demanding a nicer discrimination of shades of 

 colors which had been transmitted to the daughters as a 

 sexual peculiarity. It was for biologists to determine whether 

 a faculty, which under present conditions had no connection 

 with the sexual functions, could be transmitted as a sexual 

 peculiarity. 



No reports regarding color-blindness as affecting the dif- 

 ferent races had been made except by Magnus of Breslau. 

 He found the Jewish children affected in about 4 per cent., 

 whereas the Christian children closely approximated to 2.05 

 per cent. 



Dr. Burnett found the negro children of both sexes affected 

 to the extent of 0.78 per cent.; the boys in 1.06 per cent.; 

 girls, 0.11 per cent. This low percentage, as compared with 

 white children, he thought, might be referred to a largely 

 developed capacity for color perception in the antecedents of 

 the negroes in this country. It might be that in the earlier 

 condition of life a good perception of color was necessary for 

 their preservation, and naturally, under such circumstances, 

 those survived whose faculty in this particular was most 

 highly cultivated. 



A large number of the examinations made by him were 

 of persons of mixed blood, but often a small admixture of 

 the blood of a race seems to carry with it an immunity from, 

 or a tendency to, a disease (as shown by him in the case of 

 trochoma or granular lids, from which the negro seems to 

 be free). Hence, he infers that this may be the case in 

 anomalies in the perception of colors in the negro race. 



