102 MASS. EXPERIMENT STATION BULLETIN 191. 



3. A few instances may be added to show that the results of matings 

 between unrelated birds may be very inferior to matings between closely 

 related birds such as those just described, unless special attention is paid 

 to egg production. Thus, female No. 6982 had 10 daughters, by an unre- 

 lated male, that averaged 101 eggs each, exactly their mother's record. The 

 same male by female No. 5832, also unrelated, and laying 160 eggs, produced 

 7 daughters that averaged 151.7 eggs each. Another male, by an unrelated 

 hen that laid 234 eggs, had 9 daughters that averaged 139.1 eggs each. 



In these experiments good, strong, healthy stock has been used. The 

 families from which the males were to be chosen were selected on the basis 

 of theii' sisters' performance, and the strongest, most virile male in each 

 family selected for breeding. 



There is one thing more to be said on the subject. In our experience the 

 very best results have come from outmatings, while the very poorest have 

 come from close matings. It is dear, then, that very great care must he used 

 ivhen inbreeding, lest disaster overtake the breeder unawares. Very careful 

 and accurate pedigrees and other records must be kept. Further, the 

 provisional conclusion appears justified that the very best results are most 

 likely to be obtained by crossing two distinct lines, each of which is inbred 

 and which is doing well. Very likely the best way to renew the commercia 1 

 egg flock is through the crossing of strong, high-producing, inbred lines, 

 which will, of course, be maintained intact bj^ inbreeding, and making the 

 cross anew each season. 



II. Ls THE Influence of the Male or of the Female the more 

 Important ? 



The view that high fecundity does not descend from mother to daughter 

 but does descend from mother to son, or from father to both sons and 

 daughters is now generally accepted. This, then, leads to the belief that 

 the use of the sons of high layers insures high production in the progeny 

 sired by such sons. The male is regarded as all important, the female of 

 importance only as a producer of good males. This situation has arisen 

 apparently from the attempt to describe certain modes of inheritance in 

 every-day language. The scientific foundation, i.e., sex-linked inheritance 

 of fecundity, on which the view mentioned is based does not warrant the 

 popular interpretation which it has received. However this may be, 

 evidence is now available which indicates that high fecundity is not sex- 

 linked in some breeds, at any rate. 



In spealdng of fecundity the use of the terms high and low are not very 

 precise for they are relative; we may, however, use them with this under- 

 standing of their limitation. In this bulletin winter production only is 

 considered, because it is a fairly good index of a hen's inborn capacity 

 to lay. 



The important question to be answered is : Is it possible for high-egg 

 production to descend from mother to daughter? An experiment was made 



