252 PRINCIPLES OF STOCK-BREEDING. 



may inherit the external Short-Horn characters of one 

 parent and the internal Short-Horn characters of the 

 other parent, and thus be a pure Short-Horn ; and, in 

 another instance, the external characters of the Devon 

 may be inherited from one parent and the internal 

 characters of the Devon from the other parent, and 

 thus be a pure Devon. In other words, a pure Devon 

 and a pure Short-Horn may, according to the theory, 

 be produced from the same pair of cross-bred animals, 

 which is not only absurd, but in direct conflict with 

 all the known facts in cross-breeding. If the external 

 characteristics are represented by the numerator of a 

 fraction and the internal characteristics are represent- 

 ed by the denominator, the inherited characters of the 

 offspring, according to Mr. Walker, may be clearly 

 represented in the following diagram, in which D 

 stands for Devon and S for Short-Horn. 



Original Parents. First Produce. 



Mr. Orton, who was apparently aware of the in- 

 consistency involved in the application of this theory 

 to extreme cases, makes an admission that is fatal to 

 the theory he advocates. He says : " I do not mean 

 to imply or state that in all cases the law operates 

 with the precision I have above stated, for there are 

 certain controlling influences which confuse and mod- 



