CONFORMITY TO TYPE 271 



In the tenth generation, therefore, 2 n 1 = 1023. In 

 each 2,048 plants that arise in this generation 1,023 will 

 show constant dominant character, 1,023 will show 

 constant recessive character, and only two will be hybrids. 



Thus, there is a spontaneous tendency to escape from 

 hybridity, taking place under the most favorable condi- 

 tions with a regularity susceptible of mathematical 

 calculation and of formulation as a law. 



Spillman expresses the Mendelian law thus: "In the 

 second and later generations of a hybrid, every possible 

 combination of the parent character occurs, and each 

 combination appears in a definite proportion of the indi- 

 viduals." With more technical diction Lock defines it 

 thus: "The gametes of a heterozygote bear the pure 

 parental allelomorphs completely separated from one 

 another, and the numerical distribution of the separate 

 allelomorphs in the gametes is such that all possible 

 combinations of them are present in approximately 

 equal numbers. " . ... "The male and female germ cells 

 of hybrid plants contain each of them one or the other 

 member only of any pair of differentiating characters 

 exhibited by the parents, and each member of such a 

 pair of characters is represented in an equal number of 

 germ cells of both sexes. Separate pairs of differen- 

 tiating characters (allelomorphs) conform to this law in 

 complete independence of one another. 



DeVries expresses Mendel's law in the following simple 

 language: "The pairs of antagonistic characters in the 

 hybrid split up in their progeny, some individuals re- 

 verting to the pure parental types, some crossing with 

 each other anew, and so giving rise to new generations of 

 hybrids. ... In fertilization the characters of both 

 parents are not uniformly mixed, but remain separated, 

 though most intimately combined in the hybrid through 

 out life. They are so combined as to work together 

 nearly always, and to have nearly equal influence on all 

 the processes of the whole individual evolution. But 

 when the time arrives to produce progeny, or rather to pro- 



