8o SCIENCE PROGRESS 



Prof. Bateson, " is the very type of a polymorphic species." l 

 So polymorphic, a Darwinian might say, that Mendelians can 

 only explain him by an exercise of ingenuity which is not always 

 very convincing. For our purpose, therefore, it is necessary to 

 disentangle the evidence as to how far the military authorities 

 select soldiers on the basis of mutations, and how far on account 

 of fluctuations. This is a most difficult task. Certain diseases 

 of the eye are heritable in the Mendelian sense, and these and 

 similar instances further strengthen the case of the pessimists 

 in relation to that minority who possess definite defects. But 

 mutations do not blend with their opposites, 2 and therefore even 

 where a number of individuals with a desirable mutation are 

 lost in war, this will only reduce the proportion of individuals 

 with that mutation in the next generation, and will in no way 

 lower the standard of those who do possess the quality. 

 Moreover, variations in stature, muscular strength, powers of 

 endurance, and so on, are fluctuations, and the extremes of 

 fluctuations tend to revert rapidly to the racial mean. Human 

 height is a classic instance of a fluctuation, and this is interesting 

 in view of the legend that Napoleon " lopped a cubit off the 

 stature of the Frenchman." No doubt Napoleon succeeded in 

 reducing the height of the men of his own time, but we should 

 require convincing evidence before we could believe that the 

 Frenchman of 1913 was shorter than he of 1788. 



The foregoing considerations are sufficient to show the com- 

 plexity of the whole subject. For my part, I am inclined to 

 think that the most potent factor is probably the tendency to 

 revert to the racial mean, and this may well explain how nations 

 have passed with little change through peace and war. 



If the peoples of our continent were really to become weaker, 

 more sluggish, more stupid, more enslaved to preconceived 

 ideas, then in truth we might despair of any ultimate good 

 arising out of the present war. But I see no real cause to fear 

 degeneracy. On the contrary, we may hope for an advance, not 

 perhaps in racial qualities, but in the comprehension of our 

 environment. After terrible carnage, the iniquity of the wars of 

 religious persecution was at last realised. So may we hope 

 that this conflict will lead ultimately to some further extension 

 of the realm of justice in international affairs. 



1 Presidential Address, British Association, 1914. 



* In certain puzzling cases, however, mutations do undergo fractionation. 



