THE METHOD OF EXPERIMENTAL BREEDING 



467 



ever, always present. If red and white four o'clocks {Mirabilis 

 jalapa) are crossed, the hybrids of the Fi generation are neither red 



X 



fiii'i.. 



BLACK FOWL 



SPLASHED -WHITE FOWL 



/^ 



BLUE 



ANDALUSIAN 



FOWI^ 



INTERCROSSED 

 ^ 



■^ 



1 BLACK FOWL 



2 BLUE ANDALUSIAN FOWI^ 



1 SPLASHED - 

 WHITE FOWL 



Fig. 246. — Results of mono-hybridization of fowls which differ with re.spect to 



color of feathers. This is an example of inheritance without dominance since 



black and white parents yield blue hybrids. In the Fo generation three visibly 



distinct tyi)es are produced in a 1 : 2 : 1 ratio. 



nor white, but pink. When these pink hydrids are interbred, off- 

 spring occur in the ratio of 1 red: 2 pink: 1 white. The red and 

 white individuals breed true for these characteristic colors, while 



