172 ORIGIN OF NON-SEXUAL CHARACTERS 



these to be beyond doubt. He concludes that it is 

 impossible in the present state of knowledge to offer 

 any explanation of the origin of dominant characters. 

 In a note, however, he suggests the possibility that 

 there are no such things as new dominants. Factors 

 have been discovered which simply inhibit or 

 prevent the development of other characters. For 

 example, the white of the plumage in the White 

 Leghorn fowl is due to an inhibiting factor which 

 prevents the development of the colour factor which 

 is also present. Withdraw the dominant inhibiting 

 factor, and the colour shows itself. This is shown 

 by crossing the dominant white with a recessive 

 white, when some birds of the F 2 -generation are 

 coloured. 1 Similarly, brachydactyly in man may 

 be due to the loss of an inhibiting factor which 

 prevents it appearing in normal persons. It is 

 evident, however, that it is difficult to apply this 

 suggestion to all cases. For example, the White 

 Leghorn fowl must have descended from a coloured 

 form, probably from the wild species Gallus bankiva. 

 If Bateson's suggestion were valid we should have to 

 suppose that the loss of the factor for colour caused 

 the dominant white to appear, and then when this 

 is withdrawn colour appears again, so that the colour 

 factors and the inhibiting factors must lie over one 

 another in a kind of stratified alternation. And 

 then how should we account for the recessive white ? 

 In his Presidential Address to the meeting of the 

 British Association in Australia, 1914, Bateson 

 explains his suggestion somewhat more fully with a 

 command of language which is scarcely less re- 

 markable than the subject matter. The more true- 



1 Bateson, Principles of Heredity, p. 104. 



