110 ANALYSIS OF THE FOUR PRINCIPLES. 
ished one-eighth. In the second generation the result will be quite 
different; for variations 2 and 4 already constitute two-thirds of the 
whole number of pure-breeds. 

Second Generation— Pure-breeds. 
Of variation: . : ; : , : 5 : 250 
Of variation 2 . ; : : F : : : 1, 000 
Of variation 3 . ‘ ; : 5 : 3 , 444 
Of variation 4 . ; : : 3 : : ; 1,776 
3,470 
In this generation the decrease is only 28 individuals, or about >. 

Third Generation— Pure-breeds. 
Of variation: . , , : : : : ; 125 
Of variation 2 . , : : : : F : I, 000 
Of variation3 . i ; : : : ‘ : 296 
Of variation 4 . ; ; i f t , ; 2, 368 
3, 789 
In this generation there is an increase of 319 individuals, or a little 
over 4. 


Fourth Generatiton— Pure-breeds. 
Of variation: . , : : ; A ; : 62 
Of variation 2 . : , : P : : p 1, 000 
Of variation 3 . ; i . 4 ; : ‘ 198 
Of variation 4 . 4 : . F : : A 3a n56 
4,416 
In this generation there is an increase of 627, or of nearly +. 
Tenth Generation— Pure-breeds. 
In variation 1 . : : : ; s 5 : 0.98 
In variation 2 . ; ‘ ; : ‘ : , 1, 000 
In variation 3. ; ; 4 ; : ; : 16 
In variation 4. . . : . 5 : Sein iGys 
18,775 
Var. 4, of Tenth Generation = 1,000 (1.33334)'° computed by logarithms. 
We therefore observe that in the tenth generation variation 1 has 
become less than 1, and variation 4 has become the predominant type. 
For the next ten generations the average positive segregation will be 
advanced, (1) by the preponderance of variation 4, and (2) by the 
fact that the new variety occurs in much larger masses than at the 
beginning of the computation, and will therefore be less exposed to 
cross-fertilization. 
Now that the mass of pure-breeds is increased more than fourfold, 
it is reasonable to suppose that the ratio of pure-breeding advances. 
