260 



EEV. J. T. GULICK OH" DIYERGENT EVOLTJTION 



of offspring belonging to the one variety to which the four varia- 

 tions alike belong ? Evidently the variation represented by the 

 fraction will have the greatest influence on the following 

 generation. But as the supposed conditions allow of exact com- 

 putation, let us look at the problem a little closer. If each varia- 

 tion numbers say a thousand individuals, then the number of 

 each that will breed true will be as follows : — Of the one repre- 

 sented by y^Q, 526 will breed true and 474 will cross, 



A, 550 „ 450 „ 



J^, 555-5 „ 444-5 „ 



1% 600 „ 400 



And the next generation of each kind will be as follows : multi- 

 plying the pure parents by 10, and the hybrid pai:ents by 8 or 9, 

 according to the value of m, we have of those represented by 



-^-ff, pure off'spring 5260, hybrids 4266, 

 A, „ 5500, „ 4050, 



Ijoj J' 5555, 3556, 



A, „ 6000, „ 3200. 



There can, therefore, be no doubt that under such conditions the 

 average Prepotential Segregation and Segregate Fecundity of 

 the next generation will be considerably advanced, and so with 

 each successive generation till the average of the Pure forms is 

 represented by the fraction -f^, and is surrounded by a circle of 

 variations, of which one will be represented by the fraction 

 And from this new point continuous advance will be made toward 

 ever higher and higher grades of Segregation and Segregate 

 Fecundity ; though of course the process will be subject to 

 antagonisms and limitations arising from the principles of Self- 

 accumulating Vigour and Self- accumulating Adaptation. Let it, 

 however, be carefully noted that we have in this process the 

 manifestation of a new principle, for it rests not only on Self- 

 accumulating Positive Segregation but on Self-accumulating 

 Segregate Fecundity. 



