664 Selection of Fowls for Egg Production, [nov., 



the proportion of extremely poor producers increased. 

 There is no evidence that the quality of high egg productive- 

 ness was any more fixed in the breed at the end of the experi- 

 ments than it was at the beginning. During the last three 

 years of the experiments it was shown that a relatively small 

 environmental change is able to produce a very large differ- 

 ence in the average egg production in flocks of hens of 

 exactly the same selected ancestry. Such a result could not 

 occur if the character had been fixed by selective breeding. 



With regard to monthly production, it was found that 

 selection in this way for increased annual production had no 

 beneficial effect on winter egg production, and it was even 

 found in the experiments that the variability in monthly egg 

 production was adversely affected. It is stated that there is 

 no doubt that this system of selection failed to attain its 

 desired end, i.e., increased egg production. 



Effect of Housing on Production. — The influence of en- 

 vironment on production, and the importance of this factor 

 in drawing any conclusions as to the effect of breeding on 

 egg production, are shown by some experiments which were 

 conducted from 1904-5 onwards as to the relation of the 

 amount of floor-space per bird to egg production. The birds 

 were divided into flocks of 50, 100, and 150 birds each, and 

 put into pens with floor-space such that in the pens containing 

 50 and 100 birds there were 4*8 square feet of floor-space 

 per bird, and in the pens containing 150 birds there were 

 3*2 square feet. This small environmental difference in one 

 year produced relatively great changes in average annual 

 egg production. The average annual egg production per bird 

 was found to be distinctly lower when the hens were kept 

 in flocks of 100 birds each than when they were kept in flocks 

 of 50 birds each, though the number of square feet of floor- 

 space was the same in both cases. The production was also 

 distinctly lower when the hens were kept in flocks of 150 

 birds each than when kept in flocks of 50 and 100 birds each, 

 the floor-space in this case being smaller. In both cases, 

 however, the difference was found to lie almost entirely in 

 the economicallv unimportant summer egg production ; the 

 winter egg production was not adversely affected by keeping 



