of Heredity 9 



It was found that in each case the offspring of the cross 

 exhibited the character of one of the parents in almost 

 undiminished intensity, and intermediates which could not 

 be at once referred to one or other of the parental forms 

 were not found. 



In the case of each pair of characters there is thus 

 one which in the first cross prevails to the exclusion of the 

 other. This prevailing character Mendel calls the dominant 

 character, the other being the recessive character*. 



That the existence of such "dominant" and "recessive" 

 characters is a frequent phenomenon in cross-breeding, is 

 well known to all who have attended to these subjects. 



By letting the cross-breds fertilise themselves Mendel 

 next raised another generation. In this generation were 

 individuals which showed the dominant character, but also 

 individuals which presented the recessive character. Such 

 a fact also was known in a good many instances. But 

 Mendel discovered that in this generation the numerical 

 proportion of dominants to recessives is on an average of 

 cases approximately constant, being in fact as three to one. 

 With very considerable regularity these numbers were 

 approached in the case of each of his pairs of characters. 



There are thus in the first generation raised from the 

 cross-breds 75 per cent, dominants and 25 per cent, 

 recessives. 



These plants were again self-fertilised, and the offspring 

 of each plant separately sown. It next appeared that the 

 offspring of the recessives remained pure recessive, and 

 in subsequent generations never produced the dominant 

 again. 



But when the seeds obtained by self-fertilising the 



' Note that by these novel terms the complications involved by 

 use of the expression " prepotent " are avoided. 



