SINGLE AND DOUBLE MATING. 



187 



the blood on their own side, and are to be 

 rigorously selected true to type as before. 



But the most noteworthy mating this year, 

 to which we would call special attention, is that 

 of a pullet or pullets from group 3, with a 

 cockerel from group 4, producing group 6. It 

 will be seen that all the members of group 6 

 possess equal or half-and-half blood from the 

 original parents, as much so as group 2. We 

 also mate a pullet from group 5 and a cockerel 

 from group 7, each of these owning seven-eighths 

 of the blood of one ancestor, and we again pro- 

 duce in group 10 a progeny whose blood is half- 

 and-half. Now suppose we had mated brothers 

 and sisters from group 2 to produce the half- 

 and-half blood and age of group 6, and brothers 

 and sisters from these to produce similar equality 

 of blood at the age of group 10, the result of 

 such incestuous in-breeding would have been 

 swift degeneracy. As it is, we have made our 

 matings from lines characterised mainly by the 

 original male and female, and yet preserved the 

 same mathematically exact equality of blood in 

 our group 10. A generation farther on we can 

 produce group 15 as shown, from groups 9 and 

 II ; or we might have mated groups 8 and 12 ; 

 or the produce of the former may be mated with 

 that of the latter. We have thus seen how it is 

 possible to keep up the half-and-half blood of a 

 cross, intact and exact, without any loss of size, 

 fertility, or vigour. 



We also see plainly from this chart that by 

 the time we have reached the stage even of 

 group 10, we have got in our hands practically 

 three strai?is ; for while group 10 

 Three Strains possesses equal blood of both sides, 

 from group 8 has thirteen-sixteenths of 



One Stock. ^j^e blood of the hen, or practically 

 represents the female line ; while 

 group 12, in like proportion, possesses the blood 

 of the male line. Yet all are related sufficiently 

 to prevent evil ; and all have gone through the 

 same " course of selection " towards our own 

 fixed type. From this point we have ample 

 material to go on with indefinitely, and need not 

 pursue that matter farther. The bottom row of 

 groups simply shows some of the results in the 

 next generation. But one point more may be 

 illustrated. Suppose that for some reason — as 

 for special cockerel or pullet breeding — we want 

 to establish also a line of sires in which pre- 

 dominates the blood of the original female. The 

 chart shows a cockerel from group 5 mated with 

 a pullet from group 3, and a cockerel from the 

 produce in group 8 mated with a pullet from 

 group 10. The result in group 13 gives us the 

 same proportions of blood, but derived through 

 a cockerel line of breeding. 



Whenever a cross is necessary in a strain, 

 such a chart also shows the procedure that 

 should be followed. The cross is treated as a 

 new unit, and its produce re-mated back to the 

 home strain in the same way, carefully selecting 

 for the desired type as before. This is what 

 breeders and fanciers term " breeding back " to 

 a strain, and the philosophy of it can be clearly 

 understood from such a diagram as that before 

 us. Every cross thus involves more or less 

 breeding back to the " line " afterwards ; but 

 this need not be carried to the extent of inces- 

 tuous matings, or interfere with vigour in any 

 degree. The out-cross is not used as immediate 

 material, but to provide either pullets or cockerels 

 for really breeding into the strain the following 

 year. 



We have now considered the two main 

 factors of line or pedigree breeding, as carried 

 on by those who really understand it and prac- 

 tise it with success ; but a few 

 Single Matings remarks should be added respect- 

 er ing the question usually described 

 Double Matings. ^s that of "single or double 

 matings." Did the exhibition 

 standard of the fancier for the two se.xes of any 

 variety correspond with the relations Nature is 

 ever seeking to establish, the same mating 

 ought to produce birds of equal excellence in 

 both se.xes. But unfortunately in many varieties 

 this is not so. The reason for this in most cases 

 is pretty obvious, primarily in the differences of 

 distribution in the colours in the two sexes 

 respectively, and secondarily in the propensity 

 of fanciers either to accentuate or to diminish 

 these differences. There are instances of his 

 doing each of these. 



As a type of one case we will take the Dark 

 Brahma. This is a variety in which, like Dork- 

 ings, several colours in Game, Partridge Cochins, 

 etc., the colour is distributed in the hen amongst 

 small markings ; while in the cock it is collected 

 in large masses, of which the dark are mainly 

 upon the under, and the light coloured ones 

 upon the upper portions of the body. The 

 fancier has exaggerated this, and now seeks in 

 the pullet a uniform dark pencilling all over a 

 dirty white ground ; whilst for the cockerel he 

 wants a glossy solid black breast and fluff, with 

 nicely striped white hackles and clear wings. 

 The two, in this degree, are largely incompatible 

 as regards breeding from one pen. The nearest 

 we could come to it would be to mate with 

 pullets as described a cockerel with good striping 

 in the hackle and black breast, but the fluff 

 laced with a white edging. We might get some 

 really good pullets, such as won twenty years 



