84 THE MENDEL JOURNAL 



But after a careful study of the matter I am 

 convinced that the hypothesis of " nicking," as we 

 generally understand it, cannot adequately explain 

 the facts of the pedigree. I will proceed to explain 

 why. 



A general consideration of the parentage of 

 grey horses shows that a grey horse can never be 

 obtained imless one of the parents is a grey. No 

 exception to this statement is known. Another 

 fact throwing considerable light upon the general 

 principles of colour inheritance in horses is that 

 two grey parents need not necessarily have all 

 grey offspring, and that frequently they do produce 

 other coloured foals. These two facts thus point to 

 the conclusion that grey is dominant to all other 

 coat colours, because if it were recessive a grey 

 dam and sire coidd not produce other coat colours 

 among their offspring. Also a dam and sire of 

 some other colour would beget grey foals, but 

 this is not the case. 



If grey be thus a dominant colour, it is clear 

 that "St. Simon" could not have received any 

 grey strain from " Galopin," or " Vedette," or 

 "Mrs. Ridgway." The grey colour of "Nan Darell" 

 was in fact lost in the roan " Mrs. Ridgway," and it 

 does not re-appear in "Vedette," "Galopin," or 

 "St. Simon." Clearly, then, "Postumus" does not 

 derive his grey from the sire's side of the pedigree. 

 The hypothesis of "nicking" is therefore untenable. 



Turning next to consider where " Postumus '* 

 got his grey colour from, and why it was that " St. 



