48 THE PRACTICAL PIGEON KEEPER. 



tendency to produce crests will tave been increased enormously ; 

 and in a generation or two more it will be so strong that a 

 bird not crested will be as rare as a crested one originally was. 



We have now what is called a " strain," so far as regards 

 our one point of crest or peak. We have accumulated into one 

 direction — ^that of breeding a crest — ^the transmitting powers of 

 many successive generations, and we have thus produced a race 

 of birds which we can depend upon with almost absolute cer- 

 tainty to produce none but crested birds. Suppose, now, that 

 we have been able to keep alive for ten years (not at all an 

 impossible thing with pigeons) the pair of birds with which we 

 started in the series of operations above described. It will be 

 readily understood that they may be almost exactly similar in 

 appearance to a pair of birds we might select from the tenth 

 generation of the progeny; the closest ocular examination 

 might fail to detect any important difference ; and yet it will 

 now be clearly seen that the difference in breeding value would 

 be tremendous. The one pair have, or had — for most pigeons 

 would be past actual breeding at the age supposed — scarcely 

 any tendency to produce crests ; the other pair can be depended 

 on to do so as regards nearly every bird. One pair would 

 represent to a breeder nothing save some foundation on which 

 he might, with care and patience, found a structure hereafter ; 

 the other represents work done, qualities fixed, and a " strain " 

 which only demands ordinary care to preserve in perfection. 



So far the matter is simple enough ; and breeding would be 

 equally simple did every race possess only one point to breed 

 for. But it will readily occur to most that this is not the case ; 

 that each race is bred for several, if not for many points ; and 

 here the difficulty begins. It is, for one thing, impossible to 

 say when the tendency to revert to past faults is — ^for practical 

 purposes — lost. As to being absolutely lost, it never is ; a point 

 being known to crop up unexpectedly after twenty generations 

 of freedom from it. Hence it will appear that every time a 



