November 25, 1904.] 



SCIENCE. 



705 



races may be calculated from a collection 

 of disinterred femurs. Pearson has been 

 able to show that there is no correlation 

 between shape or size of the head and in- 

 telligence, and to demonstrate the efficiency 

 of vaccination and the non-inheritableness 

 of cancer. The opinion that various bodily 

 characteristics are bound together has been 

 substantiated by studies in the correlation 

 of all sorts of organs in plants and animals 

 and the degree of this correlation measured. 

 This index of correlation measures the 

 degree of morphological kinship or of 

 physiological interdependence. Symmetry 

 gains a quantitative expression and it is 

 interesting to find that originally non- 

 symmetrical organs which have secondarily 

 gained antimeric relations — as in animals 

 that habitually lie on one side— gain a very 

 high index of correlation. Thus I find in 

 the scallops {Pecten) which are lamelli- 

 branchs that have come to lie on the right 

 side the index of correlation between the 

 dorso-ventral and antero-posterior diam- 

 eters is 97 per cent., whereas the correlation 

 between the breadths of the right and left 

 valves is only 86 per cent. As heredity is 

 only one phase of correlation, the inherit- 

 ance of characteristics can, by the new 

 methods, be exactly measured. It is dem- 

 onstrated that there is such a thing as pre- 

 potency of one parent and that heredity is 

 weakened by change of sex. It is shown 

 that mental and physiological character- 

 istics are inherited exactly like morpholog- 

 ical characteristics; and that the relation- 

 ship between the leaves of a branch or the 

 zooids of a colony is like that between 

 brothers of a family. We learn that aU 

 inheritance is not all of one kind. That 

 certain characteristics, like stature and 

 skin color, blend in the offspring; while 

 others, like the coat color in mice, refuse to 

 blend and may be inherited according to 

 Mendel's law. 



By mathematical analysis the selection 



of particular characteristics, or those of a 

 particular degree of development, has been 

 demonstrated and the exact effect of the 

 selection process upon the frequency poly- 

 gon has been made clear. Extreme vari- 

 ants are often annihilated, although in 

 other cases the position of the mode is 

 shifted. Finally, through quantitative 

 studies the existence of local races has 

 been clearly proved— the degree of their 

 differentiation and its dependence on en- 

 vironmental conditions has been measured. 

 It has been shown that a characteristic 

 does not remain the same in all localities 

 and under all conditions, but may become 

 slightl}^ altered. This fact speaks strongly 

 for the contention that new species may in 

 some cases have arisen by the summation 

 of infinitesimal differences— that not all 

 evolution is by mutation. 



In concluding this address I am im- 

 pressed by the fact that to-day any science 

 ramifies in all directions toward every 

 other. There can be no doubt that the 

 most fruitful work in any science is to be 

 done in the border line between it and 

 some other science. There is another cor- 

 ollary to this close interweaving of the 

 sciences and that is that the existing classi- 

 fications have become antiquated. Our 

 university departments, our societies and 

 our journals still, for the most part, draw 

 the old lines. Yet the true work of science 

 has, I apprehend, overleaped the barriers 

 of these classifications, and the best workers 

 will in the immediate future be no longer 

 botanists or zoologists, or chemists or 

 mathematicians, but will be interested in 

 particular subjects— in following some fa- 

 vorable lead into the unknown. The em- 

 bryologist who is interested in processes, 

 the cytologist who is interested in the fer- 

 tilization of the egg will feel free to work 

 on any material, whether plants or animals 

 or crystals or colloidal mixtures — and by 

 any methods that seem likely to be of aid 



