THE CHERRY 127 



pedient in question is the simple one of using a 

 capital letter to designate the dominant factor of 

 any pair of unit characters, and a corresponding 

 lower case or small letter to designate the reces- 

 sive factor. 



Letting "D" for example, stand for the domi- 

 nant trait of blackness in the illustration just 

 given, and ff d JJ for the recessive trait of white- 

 ness, we may concisely state the facts of inher- 

 itance as just noted in the following formula: 



Parent ff D' J being mated with parent "d" the 

 offspring, whether few or many, bear in each in- 

 dividual case in their germ plasm the factors "D" 

 and ff d" in combination. But if two of these off- 

 spring are interbred, there will be a splitting up 

 of the factors and recombination in such wise that 

 in any average group of four of their progeny the 

 result will be this: One member that is pure 

 dominant (DD), two members that are mixed 

 dominants (Dd), and one member that is pure 

 recessive (dd). The DD individual is "homo- 

 zygous" for dominant factors and will breed true 

 to blackness. The dd individual is homozygous for 

 the recessive factors and will breed true to white- 

 ness. Tfie two Dd individuals are heterozygous 

 for the color factors, and whereas they are indi- 

 vidually black their offspring will repeat the 

 formula 1 DD + 2Dd + Idd; they will repro- 



