PHENOMENA AND PRINCIPLES OF BREEDING 465 



or rare combination of quality in their racial, family, or individual 

 characters. This peculiar capacity in reproduction is termed pre- 

 potency and individuals possessing it are said to h^ prepotent. 



As commonly used, the term "prepotency " relates only to capacity 

 to transmit desired characters. It is not a character or quality in the 

 ordinary sense of those terms. It is more appropriately described as 

 a condition of a particular individual in which it reproduces, with 

 extraordinary accuracy, its racial type or its particular type, accord- 

 ing as the condition affects or is affected by the common laws of 

 inheritance. Prepotency is not a definite condition or quality, but 

 is always relative to average or ordinary potency. An individual 

 which in the early stages of the development of a stock appears 

 prepotent might at a later stage rank low in breeding potency. It 

 has no marks distinguishing it in the individual ; consequently its 

 occurrence seems erratic. Because of the absence of distinguishing 

 marks in the individual, the bird which shows externally the highest 

 excellence in desired characters is always preferred for breeding, and 

 so undoubtedly many prepotent individuals are never given an oppor- 

 tunity to show that quality.^ Because only desirable transmissions 



1 One of the most remarkable cases of prepotency was related to me by Mr. 

 H. C. Rollins, of Woodville, Massachusetts, for many years one of the foremost 

 breeders of Light Brahmas. In making up his Brahmas one winter, he had one 

 cockerel reserved for breeding on his general appearance, but discarded him as 

 not of sufficient merit to be used in a mating from which eggs for hatching were 

 to be sold at high prices. When females had been selected to mate with the other 

 males, there were some eight or ten left over, — birds of general high quality but 

 not considered quite good enough for the regular matings. Naturally this surplus 

 stock was all put in one house. It was not considered a pen mated for breeding. 

 Not having eggs enough from the regular matings to give all he wanted for his own 

 hatching after supplying his customers, Mr. Rollins used eggs from this pen and 

 found them very fertile. Then, running short of eggs for his orders, he used eggs 

 from the same pen to fill some orders for old customers in cases where he knew 

 them and thought they would rather take the chances of these eggs than have 

 their order returned, and where, if results were not satisfactory, he could adjust 

 the matter easily. As his own chickens developed, he found the chicks from the 

 mating of discarded birds a remarkably uniform and superior lot, the average being 

 above the best of other matings. Reports from customers who had eggs from this 

 mating were to the same effect. This case, it should be noted, was in the experi- 

 ence of a man who has no superior as a breeder, and in stock bred in line by him 

 for over a quarter of a century. That the prepotent quality was in the male bird was 

 evident, for the females, while of the same stock, were not all bred alike, nor as 

 like in appearance as in regular matings. They were simply the remnants of the 

 several lines of females used in the matings of an extensive breeder. 



