CHANGES IN EGG PRODUCTION. 103 



As long as attention is fixed solely on the number of eggs laid, and no 

 recognition given to the fact that the difference between a 150-egg hen 

 and a 200-egg hen is something more than just 50 eggs, progress in getting 

 at the fundamentals of the inheritance of egg production is hindered. 

 The solution of the problem demands that the inheritance of each com- 

 ponent be ascertained by specially planned experiments. This would 

 require about fifty years of one man's time, with a flock of 500 pullets 

 trapnested through their first laying year. 



The policy which was therefore adopted at this station was, using as 

 a working theory the concept of an egg record as briefly outlined above, 

 to establish a high-producing strain by improving the flock step by step, 

 making it fairly homogeneous for one of the five characteristics and then 

 for another. In this way there would eventually be built up a flock which 

 would meet the standards required for the highest production. At the 

 same time it was planned to make an intensive study of broodiness and 

 to collect data on the other characteristics, with the purpose of gaining 

 as much useful information as possible. 



Plan of Procedure. 

 The Fotindation Stocks. 



The foundation stock as a whole proved deficient in desirable charac- 

 teristics. The birds were late maturing and, when hatched in April or 

 May, did not begin lajdng till midwinter. Many stopped producing by 

 midsummer or soon after. The winter pause was present but not con- 

 spicuous because of the late start made. Rate of production while lajdng 

 was excellent. The birds were deficient in vitality and Avere poor breeders. 

 It was essential, of course, to remedy these last two defects before further 

 work could be done. Stock of good vitality was added, but unfortunately 

 the general satisfactory rate of production was lost and the winter pause 

 accentuated, so that, as the nex^t paragraph shows, ground was lost for 

 the time being. (See Fig. 5, p. 109.) 



The members of the flock hatched in 1915 were, on the whole, late 

 maturing and broody, and exhibited a well-marked winter pause in early 

 layers, a slow rate, and a tendency to stop production early in the summer. 

 There were, however, individuals which matured earh^, others that were 

 not broody, some that laid at a high rate, some that persisted in produc- 

 tion till late fall, and some that lacked a winter pause. Individuals ex- 

 hibiting various combinations of these characteristics also occurred, but 

 there were none in which all the desired characteristics were combined. 

 This was to be accomplished by breeding, and the present plan of pro- 

 cedure, vaguely formulated the j^ear before, was put into active practice. 



Basis of Selection of Breeding Females. 

 Beginning in 1916, female breeders were selected primarily for early 

 maturity, and late maturing individuals used only when exceptional in 

 other respects. A fair approach to the objective was obtained in the 



