THE CREATION OF SPECIES 



breeding of the barnyard fowl that had been very 

 puzzling. In particular he explained certain peculiar- 

 ities of the Andalusian breed, which is sometimes 

 black, sometimes white with black splotches, and 

 sometimes slate blue. Professor Punnett showed that 

 the blue variety, which is the one prized by breeders, 

 is in reality due to the crossing of the black variety 

 with the white, whiteness acting as a recessive char- 

 acter which is bound to reappear in the offspring of 

 the blue fowl. And in point of fact, when the blues 

 are interbred, one quarter of the offspring are black 

 and one quarter are white, just as the Mendelian 

 formula requires. So the only sure way to secure a 

 full clutch of blue fowl is to breed fowls that are not 

 blue. 



Another interesting study in Mendelian heredity, 

 conducted at Cambridge by Professor T. B. Wood, 

 has to do with sheep. By application of Mendelian 

 principles, it has been found possible to cross a horned 

 and a hornless variety of a race of sheep, in such a way 

 as to do away with the horns and yet retain the qual- 

 ities of the horned ancestor. Thus crossing a black- 

 faced Suffolk ram with a white-faced ewe of the 

 horned Dorset breed produces animals with speckled 

 faces, of which the males are horned and the ewes 

 hornless. But the succeeding generation produces in- 

 dividuals combining the white face of the Dorset with 

 the hornless face of the Suffolk; and a permanent 

 breed is established in this expeditious manner. 



Doubtless the most important economic application 

 of the Mendelian experiment that has yet been made, 

 however, has been effected by Professor R. F. Biffin, 



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