MENDELIAN LAWS OF INHERITANCE 291 



bore both round and wrinkled seeds. They were hybrid like 

 the first cross, and the proportion of round seeds to wrinkled 

 ones which they produced was 3 to i . 



If we assume that each plant produces say 4 seeds, the 

 following scheme indicates the proportion of each kind obtained 

 in three successive generations : — 



(ii) That certain characters of plants are dominant over 

 others when crossing takes place was well known before 

 Mendel's time, and that among the later generation or off- 

 spring of crosses, individuals bearing the parental character 

 not seen in the first generation are obtained, was also known, 

 but the average numerical proportion of each was not noticed 

 previously. 



The most important feature of Mendel's work, however, lies 

 in the explanation which he offered of the facts. 



He propounded the hypothesis that, so far as a pair of char- 



