THE EVOLUTION OF LIVING BEINGS. 75 



,,It thus appears that if the number of separable 

 ,,hereditable characters is not very great (say not 

 above 100), while the organism has been self fer- 

 tilized for many generations, it is to be expected 

 ,,that practically all of the organisms will be homo- 

 ,,zygotic with respect to all their characters, they 

 ,,will be ,,pure homozygotes" 

 In other words this calculation leads to a result re- 

 sembling that of a Linneon, like Triticum vulgare, con- 

 sisting of a large number of different pure lines. 



Now let us see what the calculation of what hap- 

 pens in an intercrossing population of segregates from 

 a cross, will teach us. 



Calculation of what is likely to happen, if 

 free intercrossing follows an initial 

 cros between organisms, diffe- 

 ring in one or more respects. 



This has been calculated repeatedly, always with the 

 same result f. i. by Baur ad edition p. 123 129. The 

 simplest calculation I am acquainted with is by Reimers 

 in a forthcoming article on ,,Die Bedeutung des Mende- 

 lismus fur die landwirtschaftliche Tierzucht" which 

 will soon be published by Martinus Nijhoff in the Ha- 

 gue. He argues about in the following way: 

 i. The parents differ in one factor only. 



If we call this factor A and its absence a, all F t 

 individuals must be Aa. In F 2 we will find the same 

 proportions as after selffertilisation, because it is 

 of course indifferent, whether the eggcell A or a is 

 fertilised by Pollen A or a, derived from the same, 



