PRIMITIVE COLOR VISION. 51 



common form of the defect in civilized countries. Since red-green 

 blindness exists in about 4 per cent, of the male population of Europe, 

 one may conclude that this form of defective color sense was either 

 absent or was much rarer than with us. I also failed to find a case of 

 color-blindness in Kiwai and Mabuiag and among the Australian 

 aborigines, although I met with three well-marked cases of red-green 

 blindness among eight natives of the Island of Lifu, in the Loyalty 

 Group. 



As regards other colors, liowever, the case was different; blue and 

 green were constantly confused, and also blue and violet. Either owing 

 to lack of interest or to some actual deficiency in color sense, there was 

 a distinct tendency to confuse those colors for which their terminology 

 M'as deficient. I have also found this tendency to confuse green and blue 

 in several other races. 



The behavior of the people in giving names to colors also pointed 

 frequently in the same direction. I have already mentioned that in 

 Mabuiag there was a great tendency to invent names for special colors; 

 on one occasion a man, who seemed to have a special faculty in this 

 direction,- gave me as the name for a bright blue wool 'idiiridgamulnga,' 

 which meant the color of the water in which mangrove shoots had 

 been washed to make 'biiu,' an article of food. In this case there was a 

 deliberate comparison of a bright blue with dirty water, and I fre- 

 quently came across other instances of the kind, which seemed almost 

 inexplicable, if blue were not to these natives a duller and a darker 

 color than it is to us. 



This view was confirmed by quantitative observations, made with 

 Lovibond's Tintometer, which had been kindly lent to the expedition 

 by Mr. Lovibond. When the native looked into this apparatus he saw- 

 two square patches of light, either of which could be colored in any 

 intensity of red, yellow or blue by means of a delicately-graded series 

 of glasses of those colors. The 'threshold' for each color was then de- 

 termined by finding the most faintly colored glass which the native 

 could recognize and name correctly. The results showed that the na- 

 tives recognized a very faint red, a more pronounced yellow, and only 

 recognized blue when of a considerable intensity. Similar observations 

 made on a series of Englishmen showed greatest sensitiveness to yellow 

 and somewhat less to red and blue. The results may be given more 

 definitely in Mr. Lovibond's units of color; in Murray Island, red was 

 perceived on the average at .18 units, yellow at .27 and blue at .60^ 

 while the average results for the English observers were .31, .30 and 

 .36 respectively. These figures do not show anything approaching blue 

 blindness, but they do show a relative insensitiveness to blue in the 

 Murray Islander, as compared with the European. The former appears 

 nlso to be relatively more sensitive to red. 



