NEW YORK ACADEMY OF SCIENCES 619 



their images across the retina, can all be seen. A peculiarity 

 which calls for further discussion is that the apparent extent 

 of the object's motion is much less than the actual motion of 

 the eye as measured against the background. 



The author's conclusion is that vision with the moving eye is 

 essentially the same as that with the fixed eye when the external 

 field moves. 



Professor Cattell explained how he had selected a group 

 of one thousand scientific men for the study of individual 

 differences and the conditions on which success in scientific 

 work depends. In each of the twelve principal sciences the 

 students who had done original work were arranged in the 

 order of merit of their work by ten competent judges. Thus 

 was obtained the order of merit and also the proper error of 

 each position, it being based on ten independent observations. 

 This probable error is inversely as the differences in scientific 

 method, it being small where the differences are marked and 

 becoming larger as the differences are less. It is thus possible 

 to construct a curve representing the distribution of scientific 

 merit in these thousand scientific men, and this curve agrees 

 rather closely with the positive half of the curve of error. The 

 first hundred men differ among themselves about as much as 

 the next two hundred or the last seven hundred. 



Data were also given in regard to the distribution of the 

 thousand leading scientific men of the country. The birth- 

 rate of these scientific men was 27 per million of the popula- 

 tion, it being 50 in cities and 24 in the country. It was 109 

 in Massachusetts, 47 in New York, 23 in Pennsylvania, 12 

 in Missouri, and 1 in Mississippi and in Louisiana. Their present 

 distribution is somewhat similar. Thus 134 scientific men were 

 born in Massachusetts and 144 reside there; 183 were born 

 in New York and 192 reside there. The central States, with 

 the exception of Illinois, tend to lose their scientific men. 

 Thus 75 were born in Ohio, and 34 now reside there. The 

 distribution of these scientific men among different institutions 

 is as follows: Harvard, 66; Columbia, 60; Chicago, 39; Cornell, 

 33; U. S. Geological Survey, 32; U. S. Department of Agri- 

 culture, 32; Johns Hopkins, 30; California, 27; Yale. 26; Smith- 



