128 



GENETICS 



below, very nearly to the expected theoretical ratio 

 of 3 to 1. 



Darbishire repeated the yellow-green cross with 

 garden peas, obtaining in the second generation the 

 large total of 139,837 individuals of which 105,045 

 were yellow and 34,792 green, which is very close to 

 3tol. 



5. SOME FURTHER INSTANCES OF "MENDEL'S 

 LAW" 



Since the rediscovery of Mendel's law the ratio of 

 3 to 1 in the second generation has been found by 

 a number of different investigators to be constant in 

 a large array of characters observed both in animals 

 and plants of diverse kinds when these are cross-bred 

 with reference to the characters in question. 



Botanists have the advantage perhaps in this 

 matter, as they deal with forms which usually produce 

 a large number of offspring from a single cross, 

 a very desirable thing in estimating ratios. On the 



