names of Sir Francis Galton and Professor Karl Pearson. These 

 are now becoming so widely known that a detailed discussion is 

 superfluous. The coefficient of correlation, the statistician's r, meets 

 all our requirements. This constant measures the degree of similarity, 

 or interdependence, of two characters on a scale of — 1 to + 1. A 

 coefficient of ro indicates no interrelationship while r = l denotes 

 perfect interdependence. 



III. The problem of Selective Elimination. 



The scope of the paper on Selecti\'e Elimination was restricted 

 to the presentation of the data and statistical analysis necessary to 

 prove that the elimination of the ovaries occurring between the opening 

 of the flower and the ripening of the fruit is not random but selective. 



After the existence of a phenomenon is established on the basis 

 of a satisfactory body of facts, it becomes desirable to ascertain as 

 much as possible of its proximate causes. 



The simplest explanation vvhicli we can suggest for the difference 

 between the pods which reach maturity and the ovaries which fail, is 

 that the ovaries from the upper and lower regions of the inflorescence 

 are differentiated, and that the elimination does not depend directly 

 upon the character of the ovaries at all. but merely indirectly, because 

 a larger number of ovaries fail in the more distal portions of the 

 inflorescence. 



This suggestion will at once find favor with biologists. The 

 terminal flowers of an inflorescence are apt to appear smaller than 

 those nearer the base, and often a far higher percentage of them fail 

 to develop to maturity. It may be found as the result of quantitative 

 work that there is less differentiation of fruit characters due to position 

 on the inflorescence axis than is generally supposed, but however this 

 may be, it seems quite natural to suggest that the more distal regions 

 of the inflorescence have ovaries with a lower number of ovules than 

 the more proximal, and that due to the higher elimination which 

 occurs there, because of physiological factors, the mean number of 

 ovules in matured fruits is considerably higher than that in eliminated 

 ovaries. 



While casual obser\-ation furnishes some support for the opinion 

 that the more distal ovaries have a lower mean number of ovules, it 

 does not justify the assumption that they are more radialh^ asymmetri- 

 cal or contain a higher proportion of locules with an odd number of 



