OBSERVATIONS ON TABLE V. 183 



the form will in time be overwhelmed, unless other causes come in to 

 counteract ; but here we see that, if segregate fecundity occurs in the 

 ratio of 10 to 9, the pure form becomes 12 times as numerous as the 

 half-breeds; and if in the ratio of 10 to 5, it becomes 100 times as 

 numerous. 

 Second. Again, if we take the proportional differences between the 



different terms of the top line opposite c - , we shall find them very 



unlike the differences that appear in the bottom line opposite c . 



In the former the first term is 9 times as large as the last, while in the 

 latter the first term is more than 80 times as large as the last. This 

 shows that when positive segregation is intense, differences in the 

 degree of segregate fecundity produce greater contrasts than the 

 same differences do when the positive segregation is slight. 



Third. A similar distinction is found when we compare the right- 

 hand column with the left-hand column. The smallest term in the 

 former is to the largest term in the same column as i to 899, while in 

 the left-hand column the greatest is as i to 100. This shows that 

 when segregate fecundity is strongly developed, differences in the 

 degrees of positive segregation produce greater contrasts than the 

 same differences produce when the segregate fecundity is but slightly 

 developed. 



