100 



GENETICS 



side of these squares, while the arrows represent the 

 parental source from which the offspring have received 

 their hereditary composition. 



The essential feature of Mendel's law is briefly this : 

 hereditary characters are visually independent units 

 which segregate out upon crossing, regardless of tem- 

 porary dominance. 



Mendel carried on further experiments with garden 

 peas, using other characters. He obtained practically 

 the same result as in the instance already given, for 

 the actual progeny in the second generation of the 

 cross-bred offspring figured up, as seen in the table 

 below, very nearly to the expected theoretical ratio of 

 3 to 1. 



These results have been confirmed by other investi- 

 gators, for example the yellow-green seed-color cross 

 has been repeated by Correns, Tschermak, Hurst, Bate- 

 son, Lock, Darbishire and White, with results totalling 

 195,477 in the second generation of which number 

 146,802 were yellow and 48,675 were green. This is a 

 proportion of 3,016 to 1. 



