10 THE BREEDING PROBLEM. 



qTialities or characteristics, either mental or corporeal, psychological or 

 physical, in one generation, and the transmission of the same to 

 succeeding generations, and the increase, diminution or other modifica- 

 tion thereof in the offspring or descendants. 



The process here referred to embraces the operation of two forces, 

 which appear to be exactly opposite or antagonistic to each other — the 

 one a conservative force, and the other an asfffressive or disturbins: 

 force; or, as it has been well expressed. Heredity, which makes of 

 every individual the sum or essence or aggregation of that which 

 has lived before him — which opposes all change, all progress and all 

 improvement — the other. Evolution, which compels heredity to give 

 way to internal and external causes, and modifies both the phj'^sical 

 and mental organism, and places in the breeder's hands the means of 

 effecting desii-able and valuable changes. 



Of these, heredity is unquestionably the stronger force, because, as we shall 

 see, when uniformity has once been established, the general principle that like 

 produces like finds very rarely an exception. In fact, the influence of heredity 

 is always present, and in the reproduction of animal life, never fails to assert 

 itself, in a greater or less degree. Every living thing brings forth young after 

 its owJQ kind — in some cases the exact counterpart of the i^arent, and in others 

 slightly modified ; but always showing more or less of the parent type. Men 

 do not gather grapes of thorns, nor figs of thistles, neither do Short-horn cows 

 bring forth buffalo calves, nor draft mares produce thoroughbred race-horses. 

 Hence, although we may frequently meet with very apparent differences be- 

 tween the parents and the progeny, yet a moment's reflection will show us 

 that the points of resemblance are always very much greater than those of 

 difference. 



We are so accustomed to look at the operation of this law in its details, tliat 

 we overlook the aggregate of results. We mate a purely-bred 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 sliape of the ear, we find in the produce that few, 

 and possibly none possess the peculiarity which we have sought to perpetu- 

 ate, we are apt to lose faith in the power of heredity. And yet it would be an 

 argument afifaens< the uniform operation of this law were the product all to 

 possess the peculiarity which distinguished the sire and dam, for this was an 

 exceptional feature; 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 lierkshire or York- 

 ehirc pigs, there would be room for suspicion, and 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 



