GENERAL PRINCIPLES OF BREEDING. 35 



We are so accustomed to look at the operation 

 of this law in its details that we overlook the 

 aggregate of results. We mate a purely-bred 

 black Essex sow and boar, and look upon it as a 

 matter of course that the pigs produced will all 

 be black and possess the general characteristics 

 of the Essex breed; but if, having selected our 

 breeding pair with a view to the transmission 

 of a peculiar form of the head or shape of the 

 ear we find in the produce that few, and possi- 

 bly none, possess the peculiarity which we have 

 sought to perpetuate, we are apt to lose faith 

 in the power of heredity. And yet it would be 

 an argument against the uniform operation of 

 this law were the produce all to possess the 

 peculiarity which distinguished the sire and 

 dam, for this was in them an exceptional fea- 

 ture; and the fact that the pigs possessed, in 

 lieu of this peculiar mark, the character that 

 belonged to their ancestors in general is rather 

 a testimony to the inherent power of heredity 

 than otherwise. Were our pair of pure Essex 

 swine to produce Poland-China or Berkshire or 

 Yorkshire pigs there would be room for suspi- 

 cion or for complaint that the laws of heredity 

 had been violated; but such a transgression of 

 Nature's law so rarely occurs that when it does 

 take place we may properly call the result a 

 " sport." Hence, the failure of an individual 

 to reproduce features that are peculiar to itself, 



