BLENDING INHERITANCE 171 



able period provoke no little speculation among ador- 

 ing relatives as to "whose eyes" they are. 



According to Davenport, when a white Leghorn 

 fowl is crossed with a black Leghorn, white being 

 dominant in this case, chicks are produced that are 

 white with black flecks in their plumage. These black 

 flecks, however, disappear at the time of the first molt. 

 The complete dominance of white is, therefore, simply 

 delayed. 



4. "REVERSED" DOMINANCE 



In certain instances there seems to be a reversal of 

 dominance, as may be illustrated by Lang's results with 

 snails (Helix). *He has proven in his experiments that 

 red snails are generally dominant over yellow snails, 

 although in certain cases there is apparently an 

 exception to the rule, for snails with yellow shells 

 dominate those with red shells. 



Davenport has shown too that although extra toes 

 are usually dominant over the normal number in poul- 

 try, yet, in something like 20 per cent of the cases, the 

 normal number is dominant. 



It sometimes occurs that a character which is domi- 

 nant in one species may be recessive in another. Horns 

 are dominant in sheep, but recessive in cattle. White 

 color is recessive in rodents and sheep, but dominant 

 in most poultry and in pigs. 



Again Morgan describes a Drosophila that possesses 

 a gene for abnormally banded abdomen which does not 

 come to somatic expression unless the flies are supplied 

 with fresh food and a proper amount of moisture. 



