R. Haio Thomas 245 



Reversing the historv <it' the sweet pea, pheasant varieties seem to 

 ai'ise ratlier by the gain of or transposition of factors than by the loss 

 of them, except where arrested immature phimage takes the; place of 

 adult plumage. Such pheasant hybrids then may be said to have lost 

 the factor for com})]et.e adult plumage, but this ari'ested development 

 has ever been accompanied by stei-iiity. 



Examining inherited mutations one can sec that this iidieritanco is 

 governed by Mendel's law. Had it been possible in No. 1 Series to 

 have bred from all individuals of i'^, instead of only the two most marked 

 mutations, more might have been added to our knowledge of one way 

 of evolution. 



The expectation with the few numbers inevitable in pheasant- 

 breeding is that the dominant would of necessity be forced on the 

 breeder, but the results do not show this to be the case. Segregation 

 is sharp and distinct even in the day old chick, whose down forecasts 

 which parent species when adult it will most or- altogether resemble. 



Characters of Parent Species. 



The colour, size, habit and patterned or unpatternod condition of 

 the natural species used in the series of crosses dealt with in this paper 

 are briefly described. 

 Gennaeus nycthemerm (Silver) ^ . Large bird, broad Iniild. 



Colours black and white. 



Superior plumage patterned. 



Inferior plumage unpntterned. 



Li;gs rose colour. 



Habit bold, friendly to man. 

 Gennaeus nycthemerus $. Large bird, broad build. 



Colours olive grey, black and white. 



Superior plumage unpattermd. 



Inferior plumage patterned. 



Legs scarlet. 



Habit bold, friendly to man. 

 Gemiaeas siuinhoei{Svfmhoe)^. Birdsmaller than Silver, slenderer build. 



Colours metallic blue, green, and copper, white and black. 



Superior plumage patterned. 



Inferior plumage unpntterned. 



Legs dark red. 



Habit shy, seeking concealment. 



