12 



start from one at the upper end of the 

 scale of sizes, weights or what not and 

 would rise with great rapidity toward the 

 lower end, where it would reach its maxi- 

 mum. This kind of curve is not the rule. 



Every case where Galton's Law holds is 

 a case where the Law of the Minimum does 

 not hold. The resultant size or weight of 

 an organism, which is a measure of its 

 growth, shows that this is not determined 

 by the limiting factor of its environment, 

 but represents some sort of average between 

 all the factors involved. In other words, a 

 process of compensation or integration has 

 taken place, the factors giving the largest 

 values being utilized to some extent at 

 least to alleviate the influence of the limit- 

 ing factor — a utilization of surplus to cover 

 deficit. Individual processes obey the Law 

 of the Minimum; but the grand total is 

 governed by what may be termed a prin- 

 ciple of integration. 



The means by which this integration is 

 brought about are not hard to find. At 

 least four important processes are at work 

 in living organisms to this effect, namely — 



1. Responses to stimuli, 



2. Development, 



3. Evolution, 



4. Biotie succession, 



A few examples will illustrate the way in 

 which integration is effected by each of 

 these, A seedling placed upside down is in 

 the wrong position with respect to the cen- 

 ter of the earth, its source of light, and mois- 

 ture. Position with respect to gravity may 

 be considered to be the limiting factor 

 here; but the germinating rootlet is posi- 

 tively geotropic and bends toward the 

 earth; the young shoot is negatively geo- 



