OUR NATURAL INHERITANCE 69 



en'oneousness of such an interpretation is evident when 

 Blue Andalusians are paired with Blue Andalusians, 

 for then they yield 50 per cent. Blacks and 50 per cent. 

 Whites. This could never be the result of pairing two 

 similar Blends. This simple example must serve, 

 however, to suggest that results which have been 

 described as Blending Inheritance may turn out to be 

 cases of incomplete dominance in Mendelian Inheritance. 

 It is necessary to have information in regard to the Fg 

 generation. Another point must be understood. The 

 original parents may differ from one another in two 

 contrasted characters (technically called allelomorphs), 

 such as tallness and dwarfness, yellow seeds and green 

 seeds, short hair and Angora hair ; or they may differ 

 inasmuch as the one has a unit-character which the other 

 has not, as we see in cattle with or without horns, fowls 

 with or without crest, wheat with or without beard, and 

 so on. The two kinds of contrast will work out in the 

 same kind of result — the unit-character that is present 

 may act as a dominant or recessive to its own absence. 

 It must also be pointed out that the two parents 

 belonging to two pure-bred races are likely to differ 

 from one another as regards several distinct sets of 

 contrasted characters, and that this will necessarily 

 complicate results. Thus Mendel crossed a Tall Yellow- 

 seeded Pea with a dwarf green-seeded Pea, Tallness (T) 

 and Yellowness (Y) being dominants in relation to dwarf- 

 ness (d) and greenness (g), which are in this case reces- 

 sives. The hybrid offspring (Fj will all be Tall with 

 Yellow seeds (say TY). But what will be the nature of 



