On Evil in Small Doses 
who are markedly above or below the average are very 
few. The number, for instance, of individuals in England 
who are below 4 feet 6 inches or above 6 feet 6 inches 
in height is exceedingly small. The number who are 
5 feet or 6 feet in height is very great indeed, but pro- 
bably insignificant as compared with those who are 
between 5 feet 5 inches and 5 feet 7 inches. 
This natural variation about the mean has been tested 
in many ways. Thus in order to get rid of the effect of 
changes in the environment and the effect of crossing 
in the ancestry, Johansen established “ pure lines” by 
breeding from a single seed, and endeavoured to trace 
the character of the variations in its descendants.” 
The results seem to show the usual variation about a 
mean character as roughly sketched above.* 
As has been shown in a previous chapter, practical 
men do, as a matter of fact, obtain valuable varieties by 
breeding from extreme individuals much above or below 
the average in one particular character. 
In certain experiments with 40,000 sugar-beets, Messrs. 
Kuhn at Naarden in Holland found that the amount of 
sugar varied from 12 per cent. to rg per cent., with an 
average of 15.5 per cent. By selection it has been found 
possible to raise the average quite perceptibly,’ so also 
with the percentage of proteids and of oil in Indian corn, 
But by such methods the selectors are just waiting 
on the plant’s whimsies in the way. of variations. 
If we could affect or stimulate such tendencies to 
extremes, even if we could, by artificial means, changes 
of culture, and the like, set it varying, the benefit would 
be enormous. The whole process of improvement would 
be accelerated, and we might incidentally obtain that 
complete, rounded off, and satisfactory theory of evolu- 
tion which has not as yet been discovered. 
* It was first clearly stated by De Quetelet. 
328 
